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What is IP warming?

Move a full send to a fresh dedicated IP on day one and inbox providers may throttle or block most of it.

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IP warming — IP warming is the practice of slowly raising the email volume sent from a new dedicated IP address until it reaches its target. Its purpose is to give inbox providers a sending history to trust, so the new IP stays out of spam folders while its reputation forms.

Also known as: IP warmup

Why a new IP has to earn its volume

Inbox providers judge each message partly by the IP address it came from. A new IP has no history, so providers treat its mail with caution. Amazon SES docs (checked September 2026) warn that such mail "might end up in recipients' junk mail folders, or might be blocked altogether."

How long does it take? Amazon SES says some providers build a positive reputation for a new IP in around two weeks, while others may take up to six. Its own automatic warmup plan runs over 45 days. After warmup, SES suggests about 1,000 emails a day to each provider you want to keep a good standing with.

You only warm an IP you own. Do you send from Google Workspace or Microsoft 365 mailboxes? Then the sending IPs belong to the provider. What you're building is mailbox and domain reputation. That's email warmup, a related job with its own page in this glossary.

How a dedicated IP gets warmed

  1. 1

    Authenticate the domain first

    SPF, DKIM and DMARC set before any send.

  2. 2

    Start small

    A low daily volume on the new IP.

  3. 3

    Send to your most engaged contacts

    Recent openers keep complaints low.

  4. 4

    Raise volume on a schedule

    Step up each day or week.

  5. 5

    Watch bounces and throttling

    Slow down when blocks appear.

  6. 6

    Hold a steady daily floor

    A long silence lets the history fade.

Warming an IP with a cold list

The first weeks set the IP's reputation, so they should go to people who expect your mail. Teams often warm with the list they plan to prospect. Its bounces and spam complaints then land on a new IP with no good history to offset them. The reputation starts in a hole.

How sending volume is paced across your own mailboxes

SalesCrew's mailbox-pool sender spreads a cadence across your own connected mailboxes under per-mailbox and per-domain daily caps. Every bounce and complaint goes to the suppression list.

Questions

What is the difference between IP warming and domain warming?
IP warming builds the reputation of the server address that sends the mail, while domain warming builds the reputation of the name in the From address. Both build up from sending history. A shared mailbox provider handles the IP side, so most sales teams only warm domains and mailboxes.
How long does IP warming take?
IP warming usually takes two to six weeks, depending on the inbox provider, according to Amazon SES documentation checked September 2026. SES's own automatic warmup plan runs for 45 days. Larger target volumes need the longer end of that range.
Do I need a dedicated IP for cold email?
Most sales teams send cold email from standard Google Workspace or Microsoft 365 mailboxes, which use the provider's shared IPs. Amazon SES suggests about 1,000 emails a day to each provider to keep a warmed IP in good standing. A team sending a few hundred cold emails a day has too little traffic to keep a dedicated IP warm.
What happens if I stop sending from a warmed IP?
The IP's history fades, and providers start treating it with caution again. Amazon SES advises keeping around 1,000 emails a day to each provider you care about. After a long pause, restart at a lower volume and step back up.

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