# What is email warm-up? Definition and examples · Leadraft

URL: https://leadraft.co/glossary/email-warm-up
Summary: Email warm-up is gradually increasing the volume sent from a new domain or mailbox so mailbox providers learn to trust it before full campaigns.

Glossary · Email & deliverability · Last updated October 31, 2026

# Email warm-up

Email warm-up is gradually increasing the volume sent from a new domain or mailbox so mailbox providers learn to trust it before full campaigns.

**Also called:** Domain warm-up, Inbox warm-up, Warming up a domain.

A brand-new domain has no sending history, so providers treat a sudden burst of mail from it with suspicion. Warm-up means starting with a small daily volume and raising it over weeks, while keeping bounces and complaints near zero.

Many cold email tools include automated warm-up networks that exchange messages between participating inboxes. These can help a new mailbox build history, but they don't fix the things providers measure most: whether real recipients complain, and whether your list bounces. Google's guidance when mail starts being deferred or bouncing is to reduce volume until the error rate falls.

Warm-up only works on a sound setup. Authenticate the domain with SPF, DKIM and DMARC first, set up a real reply path, and make the first real campaigns go to your best, verified addresses.

For local business outreach, a practical approach is to start each new mailbox with a few dozen sends a day to verified addresses in a single trade, read every reply, and only add catch-all segments once the mailbox has a clean record.

## Example

An agency sets up three mailboxes on a new domain, authenticates it, and runs warm-up for two weeks. Its first campaign sends 30 emails per mailbox per day to verified roofing contractors, rising slowly as replies come in.

## Sources

1.  1.[Google, Email sender guidelines](https://support.google.com/a/answer/81126)

## Related terms

-   [Sender reputationSender reputation is the trust mailbox providers place in your sending domain and IP, built from complaints, bounces, authentication and engagement.](https://leadraft.co/glossary/sender-reputation)
-   [Email deliverabilityEmail deliverability is the ability of your emails to reach recipients' inboxes rather than bouncing or landing in spam.](https://leadraft.co/glossary/email-deliverability)
-   [DKIMDKIM (DomainKeys Identified Mail) is a cryptographic signature added to email so receivers can verify which domain sent it and that it wasn't altered.](https://leadraft.co/glossary/dkim)
-   [Cold emailCold email is a one-to-one business email to someone you have no prior relationship with, sent to start a conversation about a specific offer.](https://leadraft.co/glossary/cold-email)

## Further reading

-   [Cold-email checklist for agencies](https://leadraft.co/blog/cold-email-checklist-for-agencies)
-   [Leadraft for cold email](https://leadraft.co/solutions/cold-email)

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Last built: 2026-11-09