Warm up new sending IP or domain before bulk email

A brand new sending IP or domain has no established reputation with mail providers, and sending a large volume of email immediately, rather than gradually ramping up, often triggers spam filtering regardless of how legitimate the content actually is.

Reputation is built gradually through consistent, well-received sending, warming up properly is the difference between a new sending setup succeeding and getting flagged before it even has a chance.

How to do it

1. 1
   Start with small volume to your most engaged contacts

   People who reliably open and interact with your email first, this builds positive signal early.
2. 2
   Gradually increase volume over 2 to 4 weeks

   A steady ramp rather than an immediate jump to full volume.
3. 3
   Monitor deliverability and engagement closely during ramp-up

   Watch for bounce rates or spam complaints climbing, a signal to slow down further.
4. 4
   Only reach full intended volume once reputation is established

   Patience here pays off in meaningfully better long-term deliverability.