How to warm up your email for cold outreach

This guide explains how email warm-up improves deliverability and shows how to set it up in Snov.io before cold sales campaigns and during active outreach.

Warm up accounts before outreach

Email warm-up is one of the best things you can do to improve deliverability and reach the inbox. It prepares your accounts by gradually increasing sending volume and simulating real email activity with opens and replies.

Warm-up is especially important if you're creating a new setup or testing new ICP segments. After the initial period, keep warm-up active at all times to maintain deliverability.

We recommend warming up any existing accounts or done-for-you mailboxes before starting outreach. Run accounts through the initial warm-up period and do not send outreach during this time to get the full effect:

• 4 weeks: for new domains and new accounts
• 2 weeks: for existing accounts or accounts inactive for some time

If you need to start sooner, add accounts to campaigns gradually:

• add a few mailboxes after 1 week of warm-up
• add more after 2 weeks warm-up

Warm up more mailboxes to always have additional senders in your back-up. When you need to reach more prospects, add warmed-up senders from your back-up pool, not completely new accounts.

To scale easier later, get additional done-for-you accounts and put them on warm-up. This ensures you always have prepared senders ready to scale safely with mailbox rotation.

Add accounts to warm-up

Start warm-up right after connecting your accounts in Snov.io.

You can start warm-up in two ways: automatic (quick launch) or manual configuration with advanced settings.

One-click warm-up launch

Quick warm-up launch automatically selects the optimal preset based on your sender activity over the last month:

• New or low-activity accounts: gradual ramp-up to prepare accounts for campaigns
• Active accounts: fixed daily warm-up to maintain deliverability

Go to Email Accounts and use the Quick launch button under Warm-up. To launch in bulk, select accounts with checkboxes and click Start warm-up in the top panel.

Recommended warm-up presets

Here are the strategies Snov.io uses for warm-up.

For new accounts (Progressive warm-up):

• Starting volume: Number of emails sent on the first day. Warm-up starts with 2 emails by default
• Daily volume increase: Number of emails added each day. Warm-up increases by 2 emails per day
• Daily sending goal: The limit at which warm-up stops increasing. We recommend setting the warm-up goal to 40 emails per day

For existing accounts (Steady warm-up):

• Emails per day: Warm-up sends the same number of emails every day. We recommend setting this limit to 40 emails per day

The warm-up sending limit cannot be higher than your email account’s Messages per day limit. If it is set lower, we will automatically adjust the warm-up limit to the maximum allowed by your account settings.

Warm-up with a specific template

In warm-up settings, you can add your own email template, the same one you plan to use in sequences. Warm-up will send emails using this template, helping improve deliverability for that specific content.

This option works best after completing the initial warm-up with AI-generated emails. AI content is unique in every message, which makes it more effective for starting or recovering accounts. Once the initial warm-up is complete, switch to your own template in warm-up.

Manage active warm-ups

Warm-up runs automatically, and you can monitor its progress in the Warm-up dashboard.

From here, you can see which accounts are currently warming up and manage them one by one or in bulk:

• Pause or resume warm-up
• Edit warm-up settings and limits

Keep warm-up during active outreach.

Your sender reputation changes based on engagement you get from emails. Warm-up helps offset the negative signals that come with cold emailing with positive signals, like opens and replies.

We recommend keeping warm-up active at all times, during campaigns to maintain deliverability, or when outreach is paused to maintain sender reputation.

Deliverability check after warm-up

To confirm your mailboxes are ready, run a simulation sending with a Deliverability check. This test is closer to a real campaign sending scenario. 

Check these results after running tests:

• Domain health: 100% score is recommended
• Inbox rate: If inbox score is 90% or higher — your accounts are ready to launch. If it's below → extend warm-up until it reaches at least 90%
• Placement by provider: If you notice issues with spam on any provider, enable targeted warm-up for that provider

Run deliverability tests regularly: after warm-up and every week while your campaigns are active.

Set warm-up and campaign sending limits

Even after you start outreach, we recommend reserving part of your daily limit for warm-up. 

Split your sending between outreach emails and warm-up emails. When campaigns are paused, use your full daily limit for warm-up.

For cold outreach, keep your total daily sending (warm-up + campaign) at 50 emails/day or less. Exceeding this limit can negatively affect deliverability.

• during active campaigns, use about 70–80% for campaigns and 20–30% for warm-up
• for example, out of 50 emails/day: 40 outreach emails + 10 warm-up emails

Warm-up emails count as real emails, but they are not included in the Sent limit in your email accounts. Only emails sent to prospects count there. Consider both limits in your total sending when setting up your accounts.

• Set the warm-up limit in warm-up settings
• Set the campaign sending limit per mailbox in email account settings

You can update both limits for multiple accounts at once. To update in bulk: select accounts with checkboxes on email accounts or on warm-up dashboard.

Scale sending safely

For your first outreach run after warm-up, we recommend distributing limits like this:

• 10 real emails/day
• 40 warm-up emails/day

Each following week:

• Add +5 emails to the campaign sending
• Reduce warm-up by the same number

After 1 month, you'll safely reach the recommended limits per account: 40 real emails/day and 10 warm-up emails/day.

Adjust limits based on metrics

Increasing limits gradually based on engagement is the safest way to do it.

If you notice issues during deliverability tests, reduce campaign sending and increase warm-up.

• If campaigns perform well, you can increase campaign limits and lower warm-up limits
• If engagement drops, lower campaign limit and increase warm-up limits

Use reply rate and deliverability metrics as your signal for safe limit increase.

Deliverability is above 90% and Reply rate is 5% or more: increase real emails and lower warm-up emails.

If you notice issues during deliverability tests or your reply rate is below 5%, reduce campaign sending and increase warm-up.