{"id":54382,"date":"2026-06-25T13:49:14","date_gmt":"2026-06-25T10:49:14","guid":{"rendered":"https:\/\/snov.io\/blog\/?p=54382"},"modified":"2026-06-25T17:50:46","modified_gmt":"2026-06-25T14:50:46","slug":"what-affects-email-deliverability-snovio-report","status":"publish","type":"post","link":"https:\/\/snov.io\/blog\/what-affects-email-deliverability-snovio-report\/","title":{"rendered":"What Affects Email Deliverability in Cold Outreach: Our Insights from 10M+ Emails"},"content":{"rendered":"<h2>TL;DR: What affects cold email deliverability?<\/h2>\n<p>Based on our analysis of more than 10 million emails from cold outreach campaigns sent via Snov.io in May 2026, here\u2019s what affects email deliverability (both directly and via impact on engagement).*<\/p>\n<ul>\n<li><strong>Valid email authentication protocols<\/strong><strong> (SPF, DKIM, DMARC) <\/strong>result in more opens, clicks, and replies.<\/li>\n<li><strong>Custom and paid domains<\/strong> generate significantly fewer bounces than free or non-custom domains.<\/li>\n<li><strong>Personalized emails<\/strong> outperform non-personalized outreach across key engagement metrics.<\/li>\n<li><strong>Spam trigger words and attachments<\/strong> are associated with higher bounce rates and lower performance.<\/li>\n<li><strong>Domain warm-up requires active monitoring<\/strong>, especially during the 20\u201350-day period, when bounce rates tend to spike.<\/li>\n<\/ul>\n<p><em>*All aggregated data is anonymized to protect user privacy.<\/em><\/p>\n<div class=\"content-banner default\">\n<p class=\"content-banner__title\">Did you know that 1 in 6 emails lands in spam on average?<\/p>\n<p class=\"content-banner__description\">Make sure your cold emails always go to the primary inbox \u2014 not the spam folder.<\/p>\n<div class=\"content-banner__link\"><a href=\"https:\/\/app.snov.io\/register?lang=en&amp;signup_source=blog&amp;signup_page=snov.io%2Fblog%2Fsales-email-templates&amp;cta_type=banner\">Try Snov.io today<\/a><\/div>\n<div class=\"content-banner__img\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/12\/sending-emails.png\" alt=\"Did you know that 1 in 6 emails lands in spam on average\" width=\"224\" height=\"224\" \/><\/div>\n<\/div>\n<hr \/>\n<p>Let&#8217;s be honest \u2014 every cold outreach specialist is keen on improving <a href=\"https:\/\/snov.io\/blog\/guide-to-email-deliverability\/\">email deliverability<\/a>. But what most measure are the spam folder and inbox placement rates as the basic metrics, and overlook indirect, proxy signals, which often become serious pitfalls that throw the deliverability rate off its positive track.<\/p>\n<p>For this analysis, we took over 10M emails \u2014 10,105,581 messages to be exact \u2014 sent via the Snov.io platform during May 2026.<\/p>\n<p>We didn\u2019t run a seed-list test to measure direct deliverability metrics, such as spam folder and inbox placement rates, which determine the overall deliverability rate.<\/p>\n<p>Instead, our study focused on indirect campaign-level signals: engagement metrics (open, click, reply, and unsubscribe rates), along with the bounce rate, as the key indicator of email delivery.<\/p>\n<p>We wanted to demonstrate that these data are important cold email deliverability factors that can\u2019t be ignored.<\/p>\n<p>As a result, we prepared this report to help you discover actionable ways to improve your email deliverability.<\/p>\n<div class=\"table-of-contents\">\n<p class=\"table-of-contents__title\">Key points this report covers:<\/p>\n<ul>\n<li><a href=\"#how\">How email engagement metrics affect cold email deliverability<br \/>\n<\/a><\/li>\n<li><a href=\"#email\">Email delivery and engagement insights by email service provider<br \/>\n<\/a><\/li>\n<li><a href=\"#most\">Most impactful cold email deliverability factors<br \/>\n<\/a><\/li>\n<li><a href=\"#best\">Best cold email deliverability tips for 2026: Backed up by our data and experts<br \/>\n<\/a><\/li>\n<li><a href=\"#improve\">How to improve email deliverability for successful cold outreach<br \/>\n<\/a><\/li>\n<\/ul>\n<\/div>\n<h2 id=\"how\">How email engagement metrics affect cold email deliverability<\/h2>\n<p>Let\u2019s look at the average healthy open, click, reply, unsubscribe, and bounce rates in 2026 and see how they actually correlate with email deliverability.<\/p>\n<div style=\"width: 100%; display: flex; justify-content: center; margin: 2em 0;\">\n<div style=\"display: inline-block; border: 2px solid #d3d3d3; width: 100%; max-width: 900px; box-sizing: border-box; overflow: hidden;\">\n<table style=\"width: 100%; table-layout: fixed; border-collapse: collapse; margin: 0px; padding: 0px; text-align: left; height: 576px;\">\n<colgroup>\n<col style=\"width: 20%;\" \/>\n<col style=\"width: 20%;\" \/>\n<col style=\"width: 60%;\" \/> <\/colgroup>\n<thead>\n<tr style=\"background-color: #b3cdf5;\">\n<th style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 24px;\">Metric<\/th>\n<th style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 24px;\">Average benchmark<\/th>\n<th style=\"padding: 12px; text-align: center; width: 59.5982%; height: 24px;\">Impact on email deliverability<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 72px;\"><strong>Open rate<\/strong><\/td>\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 72px;\">20\u201330%<\/td>\n<td style=\"padding: 12px; width: 59.5982%; height: 72px;\"><span style=\"font-size: 12pt;\">When the open rate drops too low, mailbox providers may interpret it as a sign that people don&#8217;t want your emails. As a result, you get a poor sender reputation, hence the email deliverability rate goes down.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 72px;\"><strong>Click rate<\/strong><\/td>\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 72px;\">2\u20135%<\/td>\n<td style=\"padding: 12px; width: 59.5982%; height: 72px;\"><span style=\"font-size: 12pt;\">High click rates imply link relevance and contribute to a positive sender reputation. Very few clicks undermine it, signifying that people don\u2019t find your links worth engaging with.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 192px;\"><strong>Reply rate<\/strong><\/td>\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 192px;\">For cold outreach: 1\u20135%<br \/>\nFor email marketing campaigns: 5\u201310%<\/td>\n<td style=\"padding: 12px; width: 59.5982%; height: 192px;\"><span style=\"font-size: 12pt;\">Just like clicks, few replies may also hint at irrelevant email content, which results in unengaged subscribers and eventually ruins your sender score.<\/span><\/p>\n<p><span style=\"font-size: 12pt;\"><strong>Note:<\/strong> When reply rates suddenly collapse to zero, it\u2019s often the clearest evidence of human blocking or algorithmic spam filters when your emails land in the Junk or Spam folder automatically.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 72px;\"><strong>Unsubscribe rate<\/strong><\/td>\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 72px;\">Below 0.5%<\/td>\n<td style=\"padding: 12px; width: 59.5982%; height: 72px;\"><span style=\"font-size: 12pt;\">High opt-outs tell email providers that your messages are not just ignored but explicitly unwanted. If unsubscribe rates rise, this pattern may hurt your sender score in the long run.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 19.9777%; height: 144px;\"><strong>Bounce rate<\/strong><\/td>\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center; width: 20.3125%; height: 144px;\">Below 2%<\/td>\n<td style=\"padding: 12px; width: 59.5982%; height: 144px;\"><span style=\"font-size: 12pt;\">High bounce rates damage your IP and domain reputation and trigger spam filters, reminding of a spammer never cleaning email lists and sending to inactive or invalid addresses in bulk.<\/span><\/p>\n<p><span style=\"font-size: 12pt;\"><a href=\"https:\/\/snov.io\/knowledgebase\/what-are-hard-and-soft-email-bounces\/\">Lower bounces<\/a> \u2013 more solid sender reputation.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<p>Overall, bounce rate and reply rate are the strongest proxy signals associated with deliverability, whether in cold outreach or email marketing. That\u2019s why they are the most meaningful to track and compare.<\/p>\n<p>So, let\u2019s dive into our firsthand data, focusing on bounces, responses, and other engagement metrics and factors driving them.<\/p>\n<h2 id=\"email\">Email delivery and engagement insights by email service provider<\/h2>\n<p>The same message from the same sending domain yields different outcomes across inbox providers. We examined email metrics from 5 email providers that represent the largest datasets in our analysis: Microsoft\/Hotmail, Gmail, Zoho Mail, Yahoo\/AOL, and iCloud Mail.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider.png\" alt=\"What affects email deliverability - cold email metrics by email service provider\" width=\"745\" height=\"373\" class=\"aligncenter wp-image-54396\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider-768x384.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/cold-email-metrics-by-email-service-provider-1536x768.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Let\u2019s take a closer look at the results.<\/p>\n<h3>Microsoft\/Hotmail<\/h3>\n<p>In our study, MS\/Hotmail provides the largest dataset for analysis \u2014 over 3.9 million emails sent its way.<\/p>\n<p>Compared with other email providers, it shows the second-highest open rate, at 25.43%, after iCloud Mail.<\/p>\n<p>However, it surpasses others with the highest click rate \u2014 2.54%. On the other hand, our data demonstrate the lowest reply rate, sitting at merely 0.18%, and the lowest unsubscribe rate across all mailbox providers (0.03%).<\/p>\n<h3>Gmail<\/h3>\n<p>Gmail addresses make up the second-largest dataset of over 2.7 million emails.<\/p>\n<p>Remarkably, its 1.38% bounce rate is among the lowest of all ESPs.<\/p>\n<p>However, the open rate (15.12%) is much lower than Microsoft\u2019s.<\/p>\n<p>\ud83d\uddd2\ufe0f <strong>Note:<\/strong><\/p>\n<p><em>If you suddenly stop getting replies when sending to a Gmail recipient, this is one of the clearest signs that they might have blocked you or that you\u2019ve triggered Gmail\u2019s <\/em><em>spam filters<\/em><em>. In either case, your emails end up in their <\/em><em>spam folder<\/em><em> instead of their <\/em><em>primary inbox<\/em><em>. Naturally, your <\/em><em>email deliverability rate<\/em><em> declines.<\/em><\/p>\n<div class='posts-into__content'>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"284\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks.png\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"Como saber se algu\u00e9m me bloqueou no Gmail (testei todos os hacks)\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks.png 1672w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks-300x169.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks-1024x576.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks-768x432.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/How-to-Know-if-Someone-Blocked-You-on-Gmail-I-Tested-All-Tricks-1536x864.png 1536w\" sizes=\"(max-width: 284px) 100vw, 284px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/how-to-know-if-someone-blocked-you-on-gmail\/\">How to Know if Someone Blocked You on Gmail (I Tested All Tricks)<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">19\/06\/2026<\/p>    <\/div>\r\n<\/div>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/09\/Best-Gmail-Add-ons.png\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"melhores extensoes para o gmail \/ complementos gmail\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/09\/Best-Gmail-Add-ons.png 1500w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/09\/Best-Gmail-Add-ons-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/09\/Best-Gmail-Add-ons-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/09\/Best-Gmail-Add-ons-768x384.png 768w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/best-gmail-add-ons\/\">17 Best Gmail Add-ons for 2026 (My Honest Review)<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">25\/06\/2026<\/p>    <\/div>\r\n<\/div><\/div>\n<h3>Zoho Mail<\/h3>\n<p>Comprising nearly 64,000 emails, our Zoho Mail data shows the lowest bounce rate of all \u2014 1.20%, contributing to deliverability success, albeit indirectly.<\/p>\n<p>That said, Zoho Mail\u2019s open rate drops sharply to just 7.13%, lower than in any other email service provider.<\/p>\n<p>This may reflect users\u2019 content preferences. However, another reason could lie in the <a href=\"https:\/\/www.zoho.com\/zeptomail\/glossary\/open-tracking.html\" target=\"_blank\" rel=\"noopener\">open tracking limitations<\/a> enabled by Zoho Mail clients.<\/p>\n<h3>Yahoo\/AOL<\/h3>\n<p>With a 3.55% bounce rate in our dataset, Yahoo\/AOL emails clearly raise concerns about email delivery. It&#8217;s one of the highest, particularly 2.5x higher than Gmail&#8217;s bounce rate, as you can see in the following graph.<\/p>\n<p>The unsubscribe rate of 0.14% is also one of the highest among inbox providers.<\/p>\n<p>Despite that, Yahoo\/AOL\u2019s open and reply rates are reasonably strong when set against others.<\/p>\n<h3>iCloud Mail<\/h3>\n<p>Representing the smallest sample in our dataset (only 23,594 emails), iCloud Mail demonstrates surprisingly extreme numbers \u2014 the highest across all email providers:<\/p>\n<ul>\n<li>Open rate: 25.77%<\/li>\n<li>Reply rate: 1.43%<\/li>\n<li>Unsubscribe rate: 0.27%<\/li>\n<li>Bounce rate: 4.10%<\/li>\n<\/ul>\n<p>Here, it\u2019s worth noting that an open rate this high can be inflated by <a href=\"https:\/\/www.aurorasendcloud.com\/blog\/apple-mail-privacy-protection\" target=\"_blank\" rel=\"noopener\">Apple&#8217;s Mail Privacy Protection<\/a>. It auto-loads images, including tracking pixels, even if the recipient didn\u2019t open the message, resulting in false-positive opens.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service.png\" alt=\"Bounce rate by email service provider based on Snov.io's report\" width=\"745\" height=\"377\" class=\"aligncenter wp-image-54397\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service-300x152.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service-1024x518.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service-768x389.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Bounce-rate-by-email-service-1536x778.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>Gmail and Zoho Mail demonstrated the strongest delivery signals through the lowest bounce rates. Because open rates can be distorted by privacy features, bounce rate remains the most dependable metric for evaluating deliverability across providers.<\/em><\/p>\n<h2 id=\"most\">Most impactful cold email deliverability factors<\/h2>\n<p>The following factors significantly influence the metrics we measured:<\/p>\n<ul>\n<li>Authentication protocols (<a href=\"https:\/\/snov.io\/blog\/how-to-set-up-spf-dkim-dmarc\/\">SPF, DKIM, and DMARC<\/a>)<\/li>\n<li>Email domain age and type (free\/non-free or custom\/non-custom)<\/li>\n<li>Domain warm-up duration<\/li>\n<li>Email copy elements (personalization, link tracking, attachments, spam words, emojis)<\/li>\n<li>Email length<\/li>\n<\/ul>\n<p>And since mailbox providers heavily lean on those to evaluate your domain\/IP reputation and sender score, anything that moves them in the wrong direction likewise affects your email deliverability rate.<\/p>\n<h3>Do DKIM, SPF, and DMARC improve deliverability?<\/h3>\n<p>Yes \u2014 and we see it most obviously through the engagement metrics we tracked. Our data gives a comprehensive view of email metric changes when each of the three email authentication protocols is valid vs missing.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records.png\" alt=\"What affects cold email deliverability - email authentication records valid vs missing based on Snov.io's research\" width=\"745\" height=\"373\" class=\"aligncenter wp-image-54398\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records-1024x513.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records-768x385.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/email-authentication-records-1536x770.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Here\u2019s how authentication influences open, click, and reply rates specifically:<\/p>\n<ul>\n<li>DMARC-valid campaigns produce a 20.11% open rate compared to 17.31% for those without DMARC setup. That\u2019s roughly a 3% difference across millions of emails taken for this analysis.<\/li>\n<li>DKIM-valid campaigns show a higher click rate of 1.58% vs 1.23% for those missing this record.<\/li>\n<li>SPF-valid campaigns demonstrate identical patterns with more opens, clicks, and replies.<\/li>\n<\/ul>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>Valid <\/em><em>SPF, DKIM, and DMARC<\/em><em> records are essential elements for achieving higher <\/em><em>recipient engagement<\/em><em> (open, click, and reply rates), maintaining a <\/em><em>positive sender reputation<\/em><em> with <\/em><em>email providers<\/em><em>, and boosting your <\/em><em>inbox placement rates<\/em><em>.<\/em><\/p>\n<div class=\"content-banner default\">\n<p class=\"content-banner__title\">Are your SPF, DKIM, and DMARC records valid? Not sure?<\/p>\n<p class=\"content-banner__description\">Use Snov.io\u2019s deliverability toolkit to check and fix email authentication issues.<\/p>\n<div class=\"content-banner__link\"><a href=\"https:\/\/app.snov.io\/register?lang=en&amp;signup_source=blog&amp;signup_page=snov.io%2Fblog%2Fsales-email-templates&amp;cta_type=banner\">Start checking<\/a><\/div>\n<div class=\"content-banner__img\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2024\/12\/all-in-one2.png\" alt=\"Are your SPF DKIM, and DMARC records valid? Not sure?\" width=\"224\" height=\"224\" \/><\/div>\n<\/div>\n<h3>Does the sending domain type matter for deliverability?<\/h3>\n<p>Our research proves it does \u2013 domain type influences the bounce rate.<\/p>\n<p>See the correlation in the bar chart showing the bounce rates of free\/paid and custom\/non-custom sending domains.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type.png\" alt=\"What affects cold email deliverability - sending domain type\" width=\"745\" height=\"372\" class=\"aligncenter wp-image-54400\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type-768x384.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/sending-domain-type-1536x768.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Free domains have the highest percentage of bounced emails \u2014 3.87% \u2014 more than twice the 1.68% for paid domains. This is quite predictable because millions of people use them and, therefore, they carry a weaker domain reputation.<\/p>\n<p>Custom email domains achieve the lowest bounce rate in comparison with paid non-custom domains: 1.15% vs 3.21%.<\/p>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>The <\/em><em>sending domain<\/em><em> type affects cold <\/em><em>email delivery<\/em><em> and, as a result, deliverability. Compared to paid custom domains, their free, non-custom alternatives are associated with a measurably higher number of <\/em><em>bounced emails<\/em><em>. As a result, a <\/em><a href=\"https:\/\/snov.io\/knowledgebase\/how-to-set-up-dfy-email-accounts\/\"><em>custom <\/em><em>email infrastructure<\/em><\/a><em> with paid domains becomes the strongest delivery-focused option for cold outreach.<\/em><\/p>\n<h3>How does domain age affect email deliverability?<\/h3>\n<p>Here, the answer will be more nuanced and surprising than we anticipated, assuming that older domains may be more trustworthy with a more solid sender reputation earned over the years.<\/p>\n<p>Let\u2019s look closer at the numbers demonstrating the impact of domain age on our tracked metrics.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors.png\" alt=\"Cold email deliverability factors - sending domain age - based on Snov.io's research\" width=\"745\" height=\"375\" class=\"aligncenter wp-image-54401\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors-300x151.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors-1024x516.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors-768x387.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-deliverability-factors-1536x774.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Among all groups, domains under 1 year boast the lowest bounce rate at 1.51%, while those between 5 and 10 years have the highest at 2.94%.<\/p>\n<p>Meanwhile, opens, clicks, and replies do increase with aging domains. They hit their highest with those older than 5 years:<\/p>\n<ul>\n<li>Open rate: 22.75%<\/li>\n<li>Click rate: 1.65%<\/li>\n<li>Reply rate: 0.71%<\/li>\n<\/ul>\n<p>The unsubscribe rate, however, is lower for younger domains.<\/p>\n<p>One possible explanation for the higher bounce and unsubscribe rates among older domains is database aging. As contact lists grow over the years, they naturally accumulate inactive, outdated, or invalid email addresses.<\/p>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>Domain aging influences <\/em><em>email performance<\/em><em>. Engagement rates generally increase. However, older domains don\u2019t automatically guarantee better <\/em><em>email delivery<\/em><em> and, consequently, <\/em><em>high inbox placement rates<\/em><em>, as bounces spike with domain age.\u00a0<\/em><\/p>\n<p><em>To keep bounce rates low and engagement high, verify new contacts before outreach and regularly <\/em><a href=\"https:\/\/snov.io\/email-verifier\"><em>clean your email lists<\/em><\/a><em> by removing invalid, inactive, and unresponsive addresses.\u00a0<\/em><\/p>\n<h3>How long does it take to warm up an email domain for high deliverability?<\/h3>\n<p>The general rule of thumb says: the longer the warm-up, the better the inbox placement. Our analysis, on the other hand, suggests that the connection between the two is not always directly proportionate.<\/p>\n<p>Take a look at how the bounce rate, the most impacted metric, changes with warm-up length.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate.png\" alt=\"What affects email deliverability - warm-up duration - correlation with the bounce rate based on Snov.io's analysis\" width=\"745\" height=\"371\" class=\"aligncenter wp-image-54403\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate-300x149.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate-1024x510.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate-768x383.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/warm-up-duration-correlation-with-the-bounce-rate-1536x765.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Our research shows the following bounce rates during the shortest and longest warm-ups:<\/p>\n<ul>\n<li>&lt;5 days: 3.77%<\/li>\n<li>20\u201350 days: 4.73%<\/li>\n<li>&gt;500 days: 1.51%<\/li>\n<\/ul>\n<p>Interestingly, the 20\u201350 day warm-up window shows a considerable spike to a whopping 4.73% bounce rate \u2014 the highest in the entire dataset. Meanwhile, once the warm-up period extends beyond 50 days, bounce rates begin to decline, suggesting a positive impact on deliverability.<\/p>\n<p>As for engagement metrics, the differences aren\u2019t significant enough to mention.<\/p>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>As expected, warm-up periods longer than 2 months generally reduce bounce rates and help establish a stronger<\/em><em> sender reputation<\/em><em>. However, the trend isn&#8217;t always smooth. So, we recommend regularly monitoring deliverability rates during your warm-up process.<\/em><\/p>\n<div class='posts-into__content'>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/12\/How-to-Warm-Up-a-New-Email-Domain.png\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/12\/How-to-Warm-Up-a-New-Email-Domain.png 1500w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/12\/How-to-Warm-Up-a-New-Email-Domain-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/12\/How-to-Warm-Up-a-New-Email-Domain-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2025\/12\/How-to-Warm-Up-a-New-Email-Domain-768x384.png 768w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/how-to-warm-up-email-domain\/\">How to Warm Up a New Email Domain: The Complete DFY Setup Guide<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">29\/04\/2026<\/p>    <\/div>\r\n<\/div>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2022\/07\/BEST-EMAIL-WARM-UP-TOOL.png\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2022\/07\/BEST-EMAIL-WARM-UP-TOOL.png 1280w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2022\/07\/BEST-EMAIL-WARM-UP-TOOL-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2022\/07\/BEST-EMAIL-WARM-UP-TOOL-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2022\/07\/BEST-EMAIL-WARM-UP-TOOL-768x384.png 768w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/email-warm-up-tools\/\">13 Best Email Warm-Up Tools (Tested And Compared)<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">2\/06\/2026<\/p>    <\/div>\r\n<\/div><\/div>\n<h3>What are copy-related cold email deliverability factors?<\/h3>\n<p>While researching what affects email deliverability, we also analyzed how email metrics vary depending on whether cold email campaigns include personalization, link tracking, spam words, attachments, and emojis.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors.png\" alt=\"Template-related cold email deliverability factors based on Snov.io's research\" width=\"745\" height=\"375\" class=\"aligncenter wp-image-54406\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors-300x151.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors-1024x516.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors-768x387.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Template-related-cold-email-deliverability-factors-1536x774.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Here are our key findings:<\/p>\n<p><strong>Personalization<\/strong><\/p>\n<p>Personalized email campaigns are associated with substantially higher recipient engagement.<\/p>\n<p>The open rate (20.79%) illustrates this tendency best in the graph below.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics.png\" alt=\"Cold email engagement metrics depending on personalization\" width=\"745\" height=\"376\" class=\"aligncenter wp-image-54407\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics-300x151.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics-1024x516.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics-768x387.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Cold-email-engagement-metrics-1536x775.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>The higher bounce rate (2.55% vs 1.29%) may suggest that personalized email campaigns were sent to more targeted, manually collected (but not verified) lead lists with more invalid addresses.<\/p>\n<p><strong>Link tracking<\/strong><\/p>\n<p>Messages with tracked links have a lower bounce rate (1.15% vs 2.59%) and a higher open rate (21.44% vs 13.95%).<\/p>\n<p>The 0.00% click rate is expected \u2014 clicks aren&#8217;t calculated when tracking is disabled.<\/p>\n<p><strong>Spam trigger words and <\/strong><strong>attachments<\/strong><\/p>\n<p>The presence of <a href=\"https:\/\/snov.io\/blog\/550-spam-trigger-words-to-avoid\/\">spam trigger words<\/a> is associated with significantly higher bounce rates: 3.43% versus 1.53% for emails free of spam-like vocabulary.<\/p>\n<p>Along with spam words, attached files also increase the bounce rate: 2.98% against 1.86% for emails without attachments.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments.png\" alt=\"Factors that ruin cold email deliverability - spam words and attachments\" width=\"745\" height=\"376\" class=\"aligncenter wp-image-54408\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments-300x151.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments-1024x516.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments-768x387.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/spam-words-and-attachments-1536x775.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>In addition, attachments also reduce all positive engagement metrics: open, click, and response rates.<\/p>\n<p><strong>Emojis<\/strong><\/p>\n<p>Click and reply rates are higher with emojis (2.97% vs 1.22% and 0.64% vs 0.48%).<\/p>\n<p>At the same time, the bounce rate is also higher, and the unsubscribe rate more than doubles (0.11% vs 0.05%).<\/p>\n<p style=\"text-align: center;\"><iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"\/\/www.youtube.com\/embed\/aJ3gPwThXAs?si=k3E0YnU_cGrmQ-Qi\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>Personalization is the strongest engagement-booster among all template-related <\/em><em>cold email deliverability factors<\/em><em>. Meanwhile, adding attachments and spam words is the biggest red flag. As for emojis, be careful, especially if your email deliverability is not perfect at the moment.\u00a0<\/em><\/p>\n<h3>Should cold emails be long or short for successful inbox placement?<\/h3>\n<p>According to our research, it\u2019s better to keep cold emails on the shorter-to-medium side to reduce bounce and unsubscribe rates, although recipient engagement is more length-driven.<\/p>\n<p><a href=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words.png\" data-fancybox=\"\"> <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words.png\" alt=\"What affects cold email deliverability - number of body words based on Snov.io's research\" width=\"745\" height=\"372\" class=\"aligncenter wp-image-54409\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words.png 1999w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words-768x384.png 768w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/number-of-body-words-1536x768.png 1536w\" sizes=\"(max-width: 745px) 100vw, 745px\" \/> <\/a><\/p>\n<p>Here are our key findings:<\/p>\n<ul>\n<li>Bounce rate goes up with email length, peaking at 3.18% (500\u20131,000 words)<\/li>\n<li>Open rate peaks at 21.61% for the longest emails (yet, they comprise the smallest sample)<\/li>\n<li>Click rate is 0.00% for &lt;100 words (most likely, no links in short emails = zero clicks); spikes to 8.28% for longer messages<\/li>\n<li>Reply rate is the highest for &gt;5,000 words (again, a small sample)<\/li>\n<li>Unsubscribe rate climbs to 0.15% for longer emails<\/li>\n<\/ul>\n<hr \/>\n<p><strong>Key takeaways:<\/strong><\/p>\n<p><em>Messages under 100 words are the safest solution for cold email deliverability. If you want to experiment with long reads, it&#8217;s better to A\/B test your campaigns first to find the optimal email length based on your audience.<\/em><\/p>\n<h2 id=\"best\">How to improve email deliverability for successful cold outreach<\/h2>\n<p>Follow expert advice supported by the key discoveries and conclusions from our 2026 cold email report.<\/p>\n<h3>Set up and monitor your email authentication protocols<\/h3>\n<p>Literally all cold outreach experts\u2019 tips on deliverability optimization begin with or include this trio. Here\u2019s one of them.<\/p>\n<blockquote class=\"blockquote-with__image\"><p>I thought great copy was the secret to cold email. Then I realized 80% of my emails were landing in spam. Here\u2019s what we found. [&#8230;] Authentication is non-negotiable. SPF, DKIM, and DMARC are the foundation ESPs check before letting anything through.<\/p>\n<div class=\"blockquote-image\">\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Alex-Vacca.jpg\" alt=\"Alex Vacca\" width=\"48\" height=\"48\" \/><\/p>\n<div class=\"blockquote-image__info\">\n<p class=\"blockquote-image__info-author\">Alex Vacca<\/p>\n<p class=\"blockquote-image__info-position\">Co-Founder of ColdIQ<\/p>\n<\/div>\n<\/div>\n<\/blockquote>\n<p>Our findings also confirm that engagement metrics \u2014 opens, clicks, and replies \u2014 drop significantly when these email authentication records are missing. Not to mention that it\u2019s a must to have them authenticated if you\u2019re reaching out to Gmail email clients in particular. It\u2019s a mandatory requirement in <a href=\"https:\/\/snov.io\/blog\/email-sender-guidelines\/\">Gmail\u2019s sender guidelines<\/a>:<\/p>\n<ul>\n<li>SPF or DKIM for all senders<\/li>\n<li>SPF, DKIM, and DMARC for bulk senders (&gt; 5,000 emails daily)<\/li>\n<\/ul>\n<p>You can run a DKIM, SPF, or DMARC check separately with tools like Dmarcian or EasyDMARC, or launch an all-encompassing <a href=\"https:\/\/snov.io\/email-deliverability-test\">Email Deliverability Test<\/a> via the Snov.io platform to determine whether all three are functioning properly.<\/p>\n<p>You\u2019ll also get actionable expert recommendations on how to fix cold email deliverability problems, if any are detected.<\/p>\n<p><script> function onArcadeIframeMessage(e) { if (e.origin !== 'https:\/\/demo.arcade.software' || !e.isTrusted) return; const arcadeIframe = document.querySelector(`iframe[src*=${e.data.id}]`); if (!arcadeIframe || !arcadeIframe.contentWindow) return; if (e.data.event === 'arcade-init') { arcadeIframe.contentWindow.postMessage({event: 'register-popout-handler'}, '*'); } if (e.data.event === 'arcade-popout-open') { arcadeIframe.style['position'] = 'fixed'; arcadeIframe.style['z-index'] = '9999999'; } if (e.data.event === 'arcade-popout-close') { arcadeIframe.style['position'] = 'absolute'; arcadeIframe.style['z-index'] = 'auto'; } } window.addEventListener('message', onArcadeIframeMessage); <\/script><\/p>\n<div style=\"position: relative; padding-bottom: calc(56.79180887372014% + 41px); height: 0; width: 100%;\"><iframe style=\"position: absolute; top: 0; left: 0; width: 100%; height: 100%; color-scheme: light;\" src=\"https:\/\/demo.arcade.software\/0z2aNvroNdCuHjkcF8rc?embed&amp;embed_mobile=modal&amp;embed_desktop=inline&amp;show_copy_link=true\" title=\"Introduction to Deliverability Check\" frameborder=\"0\" loading=\"lazy\" webkitallowfullscreen=\"webkitallowfullscreen\" mozallowfullscreen=\"mozallowfullscreen\" allowfullscreen=\"allowfullscreen\" allow=\"clipboard-write\"><\/iframe><\/div>\n<h3>Organize contact list cleanups before launching email campaigns<\/h3>\n<p>The peaking bounce rate, as you\u2019ve seen in numerous datasets across our report, may become the primary underminer of your sender reputation and inbox placement. To prevent it from sabotaging your efforts, clean your contact lists whenever you\u2019re about to launch another campaign.<\/p>\n<blockquote class=\"blockquote-with__image\"><p>Inactive or invalid addresses or risky ones, such as catch-all, disposable, and so on, can account for up to 60% of the entire email list. That\u2019s why verifying emails and cleaning up your list before each campaign is the groundwork. The foundation, without which your cold outreach will fall into the digital abyss after the first 100 emails sent, domains will go to spam for 3-5 weeks, and your email campaigns will simply stop.<\/p>\n<div class=\"blockquote-image\">\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2024\/11\/Dmytro-Krasiuk.png\" alt=\"Dmytro Krasiuk\" width=\"48\" height=\"48\" \/><\/p>\n<div class=\"blockquote-image__info\">\n<p class=\"blockquote-image__info-author\">Dmytro Krasiuk<\/p>\n<p class=\"blockquote-image__info-position\">Outbound Outreach Expert at Snov.io<\/p>\n<\/div>\n<\/div>\n<\/blockquote>\n<p>When performing a contact list cleanup, get rid of the following:<\/p>\n<ul>\n<li>Inactive addresses<\/li>\n<li>Non-existent or invalid addresses<\/li>\n<li>Incorrect addresses with typos<\/li>\n<li>Catch-all addresses<\/li>\n<li>Spam trap addresses<\/li>\n<li>Disposable (temporary) addresses<\/li>\n<\/ul>\n<p><strong>Case study:<\/strong><\/p>\n<p>Arquitetura de Vendas ran bulk validation and list cleaning with Snov.io <a href=\"https:\/\/snov.io\/email-verifier\">Email Verifier<\/a> and found out that only 446 out of 2,100 contacts were valid for their cold email campaigns. That\u2019s roughly one in five! With the cleaned-up email list, their messages reached the right people and landed in inboxes instead of bouncing back and undermining their sender reputation.<\/p>\n<div class='posts-into__content'>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/02\/1-1.png\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"Email Hygiene Is Easy: 8 Best Email List Cleaning Practices\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/02\/1-1.png 1500w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/02\/1-1-300x150.png 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/02\/1-1-1024x512.png 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/02\/1-1-768x384.png 768w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/email-list-cleaning\/\">Email Hygiene Is Easy: 8 Best Email List Cleaning Practices<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">21\/05\/2026<\/p>    <\/div>\r\n<\/div>\r\n<div class=\"post\">\r\n    <div class=\"post__img\">\r\n        <img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"160\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2018\/09\/Best-Email-Verification-Services-of-2026-2.jpg\" class=\"attachment-327x160 size-327x160 wp-post-image\" alt=\"\" srcset=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2018\/09\/Best-Email-Verification-Services-of-2026-2.jpg 1500w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2018\/09\/Best-Email-Verification-Services-of-2026-2-300x150.jpg 300w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2018\/09\/Best-Email-Verification-Services-of-2026-2-1024x512.jpg 1024w, https:\/\/snov.io\/blog\/wp-content\/uploads\/2018\/09\/Best-Email-Verification-Services-of-2026-2-768x384.jpg 768w\" sizes=\"(max-width: 320px) 100vw, 320px\" \/>    <\/div>\r\n    <div class=\"post__content\">\r\n        <p class=\"post__content-title\">\r\n            <a href=\"https:\/\/snov.io\/blog\/email-verification-services\/\">Best Email Verification Services of 2026: My Test and Honest Review<\/a>\r\n        <\/p>\r\n        <p class=\"post__content-date\">24\/06\/2026<\/p>    <\/div>\r\n<\/div><\/div>\n<h3>Warm up your sending domains more carefully<\/h3>\n<p>As our report demonstrated, 20\u201350 warm-up days are associated with the largest number of bounced emails. This is typically the phase where many senders scale email volume before their domain reputation stabilizes, and the bounce rate pays the cost of that decision. But then, what\u2019s the best practice and sending volume for warming up your email domain?<\/p>\n<p>Here\u2019s the practical warm-up implication from our expert.<\/p>\n<blockquote class=\"blockquote-with__image\"><p>This risky window requires thorough monitoring, not just a phase to push through more messages. Your quick reaction to bounces, spam complaints, and other live signals matters more than a raw warm-up duration factor. Once the bounce rate climbs above 2% at any point, slow down and let your sender reputation stabilize before increasing email volume again.<\/p>\n<div class=\"blockquote-image\">\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/05\/Artur-Oleksiuk.jpg\" alt=\"Artur Oleksiuk\" width=\"48\" height=\"48\" \/><\/p>\n<div class=\"blockquote-image__info\">\n<p class=\"blockquote-image__info-author\">Artur Oleksiuk<\/p>\n<p class=\"blockquote-image__info-position\">Email Deliverability Expert at Snov.io<\/p>\n<\/div>\n<\/div>\n<\/blockquote>\n<p>Speaking about volume, you should pay sharper attention to the precise <a href=\"https:\/\/snov.io\/blog\/email-sending-limits-of-email-service-providers\/\">daily sending limits of email providers<\/a>.<\/p>\n<p><strong>For example:<\/strong><\/p>\n<p>If you compare <a href=\"https:\/\/support.microsoft.com\/en-US\/Outlook\/sending-limits-in-outlook-com\" target=\"_blank\" rel=\"noopener\">Microsoft Outlook<\/a> and <a href=\"https:\/\/support.google.com\/mail\/answer\/22839\" target=\"_blank\" rel=\"noopener\">Gmail<\/a>, the former allows 10x more daily recipients for free accounts: 5,000 compared to only 500. However, both may penalize those who suddenly start sending messages in bulk without properly warming them up first.<\/p>\n<p>So, start warming up your account with 2 emails\/day and gradually increase your email volume to build your domain and IP reputation bit by bit. Avoid sending emails in spikes and stick to the recommended safe limit of 30 emails\/day for cold outreach.<\/p>\n<div class=\"content-banner default\">\n<p class=\"content-banner__title\">Reach a 98% inbox placement rate with Snov.io<\/p>\n<p class=\"content-banner__description\">Enjoy DFY email infrastructure, email warm-up, email verification, and more!<\/p>\n<div class=\"content-banner__link\"><a href=\"https:\/\/app.snov.io\/register?lang=en&amp;signup_source=blog&amp;signup_page=snov.io%2Fblog%2Fsales-email-templates&amp;cta_type=banner\">Get started <\/a><\/div>\n<div class=\"content-banner__img\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2023\/12\/all-in-one2.png\" alt=\"Reach a 98 inbox placement rate with Snov.io\" width=\"224\" height=\"224\" \/><\/div>\n<\/div>\n<h3>Revisit your templates and refine your email content<\/h3>\n<p>Our analysis of over 10 million messages made it clear that several template factors put both recipient engagement and deliverability at risk. So, we\u2019ve rounded up a comprehensive list of template-related tips for improving cold email deliverability and engaging recipients more effectively.<\/p>\n<p>They are represented in the following table.<\/p>\n<div style=\"width: 100%; display: flex; justify-content: center; margin: 2em 0;\">\n<div style=\"display: inline-block; border: 2px solid #d3d3d3; width: 100%; max-width: 900px; box-sizing: border-box; overflow: hidden;\">\n<table style=\"width: 100%; table-layout: fixed; border-collapse: collapse; margin: 0; padding: 0; text-align: left;\">\n<colgroup>\n<col style=\"width: 25%;\" \/>\n<col style=\"width: 75%;\" \/> <\/colgroup>\n<thead>\n<tr style=\"background-color: #b3cdf5;\">\n<th style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\">Template factor<\/th>\n<th style=\"padding: 12px; text-align: center;\">Recommendation<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\"><strong>Personalization<\/strong><\/td>\n<td style=\"padding: 12px;\"><span style=\"font-size: 12pt;\">Segment your email list and personalize each message.<\/span><\/p>\n<p><span style=\"font-size: 12pt;\">For example: \u201cHey [First Name], saw your recent LinkedIn post on [Topic]. The [Location] market is really hard to tap into. But your team did it, congrats!\u201d<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\"><strong>Spam words<\/strong><\/td>\n<td style=\"padding: 12px;\"><span style=\"font-size: 12pt;\">Remove spam trigger words from your subject lines and email bodies.<\/span><\/p>\n<p><span style=\"font-size: 12pt;\">For example: \u201cQuick question\u201d is often overused in cold emails. \u201cAct now\u201d is a typical spam-triggering word in marketing emails.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\"><strong>Link tracking<\/strong><\/td>\n<td style=\"padding: 12px;\"><span style=\"font-size: 12pt;\"><a href=\"https:\/\/snov.io\/knowledgebase\/how-to-track-clicks-on-a-link-in-email-campaigns\/\">Track link clicks<\/a> more carefully with a custom tracking domain to avoid triggering spam filters.<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\"><strong>Attached files<\/strong><\/td>\n<td style=\"padding: 12px;\"><span style=\"font-size: 12pt;\">Replace attachments with links, but don\u2019t overuse them.<\/span><\/p>\n<p><span style=\"font-size: 12pt;\">For example: \u201cHere\u2019s your copy [link]\u201d instead of \u201cSee your PDF copy attached.\u201d<\/span><\/td>\n<\/tr>\n<tr style=\"border-top: 2px solid #d3d3d3;\">\n<td style=\"padding: 12px; border-right: 2px solid #d3d3d3; text-align: center;\"><strong>Emojis<\/strong><\/td>\n<td style=\"padding: 12px;\"><span style=\"font-size: 12pt;\">Be careful with emojis in cold outreach \u2014 you\u2019ve got data-backed reasons to avoid them for unsegmented recipients. Or at least limit their usage.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<p><strong>Note:<\/strong> If you do want to experiment with the emoji language in your cold email campaigns, be mindful of your target audience, as there\u2019s still an ongoing \u201cemoji debate\u201d in professional communications.<\/p>\n<blockquote class=\"blockquote-with__image\"><p>Match your audience. If your recipient uses emojis, mirroring their style can build rapport. Use emojis thoughtfully. They can help, but can they also backfire? \u2014 especially across generations.<\/p>\n<div class=\"blockquote-image\">\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/snov.io\/blog\/wp-content\/uploads\/2026\/06\/Yurii-Veremchuk.jpg\" alt=\"Yurii Veremchuk\" width=\"48\" height=\"48\" \/><\/p>\n<div class=\"blockquote-image__info\">\n<p class=\"blockquote-image__info-author\">Yurii Veremchuk<\/p>\n<p class=\"blockquote-image__info-position\">Outbound Sales Consultant<\/p>\n<\/div>\n<\/div>\n<\/blockquote>\n<p><strong>Case-study:<\/strong><\/p>\n<p>Theo Seel Kent, Co-Founder of Clayworks, faced 3 <a href=\"https:\/\/www.linkedin.com\/posts\/theo-seel-kent_i-spent-the-last-6-months-trying-to-figure-share-7335437832515145730-s0RO\/\" rel=\"nofollow noopener\" target=\"_blank\">deliverability issues<\/a> impacting his open rate. One of them was the subject lines triggering spam filters and sending his messages to the Spam folder. Once he removed spam trigger words like \u201c<em>Dear<\/em>,\u201d better known as the \u201cD-word\u201d in email marketing, opens increased by 8% instantly.<\/p>\n<p>Overall, he raised his open rate from as low as 12% to an impressive 47% after handling the other two problems: fixing the broken email authentication records (SPF, DKIM, and DMARC) and switching to a dedicated IP address to avoid the one shared with spammers.<\/p>\n<h2 id=\"improve\">What affects email deliverability: Key takeaways<\/h2>\n<p>Here\u2019s a brief rundown of our key report insights after analyzing over 10 million cold emails and follow-ups:<\/p>\n<ul>\n<li>Cold email campaigns get delivered more reliably to Zoho Mail and Gmail users, showing the lowest bounce rates.<\/li>\n<li>Email authentication protocols are the core technical setup. Campaigns with valid SPF, DKIM, and DMARC records drive opens, clicks, and responses.<\/li>\n<li>Free and non-custom domains have significantly higher bounce rates. So, paid and custom domains are more beneficial for cold outreach.<\/li>\n<li>Warm-up for 20\u201350 days requires more careful monitoring. The bounce rate is the highest during this timeframe.<\/li>\n<li>Shorter emails are the safest choice for cold outreach. Messages under 100 words achieve the lowest bounce rate in the body-length dataset.<\/li>\n<li>Template choices are crucial for both recipient engagement and delivery. While personalization boosts open rates, spam words and attachments double the bounce rate.<\/li>\n<\/ul>\n<p>The effect of negative signals may be cumulative, turning into an unstoppable avalanche of consequences to your reputation. And let&#8217;s be real \u2014 a poor sender reputation is much harder to recover and rebuild than deleting one spam word from your template or fixing a one-time technical issue. Let <a href=\"https:\/\/snov.io\/email-deliverability-test\">Snov.io<\/a> help you with all the necessary fixes right away.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Snov.io analyzed 10M+ emails to find out what affects email deliverability in cold outreach. See our analysis results and learn how to improve cold email deliverability.<\/p>\n","protected":false},"author":123,"featured_media":54418,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1929],"tags":[1978,2037,2118],"_links":{"self":[{"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/posts\/54382"}],"collection":[{"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/users\/123"}],"replies":[{"embeddable":true,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/comments?post=54382"}],"version-history":[{"count":17,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/posts\/54382\/revisions"}],"predecessor-version":[{"id":54482,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/posts\/54382\/revisions\/54482"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/media\/54418"}],"wp:attachment":[{"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/media?parent=54382"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/categories?post=54382"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/snov.io\/blog\/wp-json\/wp\/v2\/tags?post=54382"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}