How to verify your email list before outreach

This guide explains how to verify emails with Snov.io's Email Verifier to avoid outreach on risky or inactive emails.

Verification confirms whether an email address is valid and safe to contact. Verified lists reduce bounces, protecting your sender reputation.

Verify prospect list

When you collect prospects with our Finder tools, emails are pre-verified.

If you import your own email list, you can verify it using the built-in verification. Open the list and click Verify emails in the top toolbar.

How verification works

After verification, each email gets one of these statuses:

• Valid (green): The address is active and passed all checks
• Unverifiable (yellow): The address may work, but the owner's domain settings don't allow a 100% verification
• Invalid (red): The address doesn't exist or can't accept emails

Each verification uses 1 credit from your account balance. Invalid emails are not verified and don't use credits.

Check list health

We recommend checking your list using these factors before launching a campaign.

Lead source

Leads collected in Snov.io → our database refreshes monthly and provides pre-verified contacts.

Leads imported from any external source (CSV file, integrations, CRMs) → verify the list with Bulk Email Verifier.

Freshness check

Use leads that were collected and verified no more than 2 months before outreach. If the list is older, you'll need to monitor bounces more closely.

Green vs yellow emails ratio

After verification, check how many yellow (unverifiable) emails are in the list. Yellow emails couldn't be confirmed as valid and carry a higher bounce risk — they require extra care before sending.

Open your prospect list and filter by email status in the top right corner. The numbers there show how many emails you have in each status.

Here's how we recommend assessing your list:

• Healthy list (5% or less yellow): For every 100 prospects, up to 5 have yellow emails. You may still get a few bounces, but it's safe to launch a campaign.
• Not healthy (more than 5% yellow): For every 100 prospects, more than 5 have yellow emails. Such lists are risky to send at full volume. Clean the list before launching

When there are enough verified emails to start a campaign, the list displays a List ready for outreach label.

Note: this 5% refers to the share of unverifiable emails in your list, not your campaign bounce rate. For bounce rate guidance, see Monitor bounce rate below.

Clean the list

Filter yellow emails before sending and remove the ones most likely to hurt your sender reputation.

Yellow emails have a higher bounce risk. Hover over the status icon to see details and understand why an address is marked as yellow.

We recommend removing catch-all addresses from your list, since they usually produce most bounces among yellow emails.

What's the safest way to use yellow emails?

Yellow emails may still accept messages and convert into leads, so removing all of them can mean missing valuable contacts. Instead:

• Add yellow emails gradually, a few prospects at a time
• Consider your current deliverability, email account health, and sender domain reputation before including them
• Don't add a large batch of yellow emails without reviewing them first

Don't use yellow emails in campaigns if:

• Campaigns are already facing deliverability problems and have a high bounce rate
• Your email accounts haven't been warmed up yet. Start a warm-up
• Your domain's health needs improvement. Check the domain's health

Do-not-contact list

After cleaning your list, set up a do-not-contact list. You'll use it in campaigns to automatically exclude prospects you should never contact. Add the following to it:

• Prospects who unsubscribed, asked not to be contacted, or replied not interested
• Bounced emails you don't want to retry, including hard bounces
• Duplicates, competitors, or any contacts you want to avoid
• High-risk yellow emails, such as catch-all addresses

Monitor bounce rate

Bounce rate is one of the clearest signals of list health. Monitor it more closely for lists with yellow emails.

Your goal is to keep the bounce rate at 5% or lower. Snov.io will automatically pause a campaign if the bounce rate reaches 15% to protect sender reputation.

• Bounce rate 1–2%: Great result
• Bounce rate 3–5%: Acceptable, but list health needs attention. Add yellow emails only in small batches
• Bounce rate 5% or more: Risky for sender reputation. Don't add more yellow emails until the rate goes down

Filter recipients by engagement

Check which results come from prospects with yellow emails, such as opens, replies, and bounces.

See the guide on how to filter recipients.

Filter prospects without opens

If a recipient hasn't opened any emails even after follow-ups, it may indicate a delivery issue. Low engagement can also hurt sender reputation.

How to filter:

• Go to the Recipients tab in your campaign
• Use the Filter menu in the top left to show recipients with Active status and 0 views

What to do next:

• Move them to a separate list
• Change their status to Paused to stop the sequence
• Add them to your do-not-contact list

Filter bounced emails

Snov.io automatically detects most types of bounces. Recipients with a Bounced status won't receive follow-ups.

How to filter:

• Go to the Recipients tab in your campaign
• Use the Filter menu in the top left to show recipients with Bounced status

What to do next:

• Remove bounced contacts from your campaign
• Add them to your do-not-contact list

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