Guide
How to warm up a new mailbox for cold email
Warmup is the process of slowly building a sending history for a new mailbox so inbox providers learn to trust it. Skipping it is the most common reason new cold email setups land in spam.
Why new mailboxes need warming up
Inbox providers judge mail partly on the sender's history. A mailbox with no history that starts sending large volumes looks exactly like a compromised account or a spammer. Warmup gives providers a few weeks of normal-looking activity first.
A simple warmup schedule
Exact numbers vary, but a cautious schedule looks like this:
- Week 1: 5 to 10 emails a day, mostly warmup conversations
- Week 2: 15 to 25 a day, start a small real campaign
- Week 3: 30 to 40 a day, keep warmup running alongside
- After that: hold around 30 to 50 cold emails a day per mailbox
Mistakes that undo warmup
Warmup cannot save a mailbox that then does these things:
- Jumping straight to full volume once warmup ends
- Sending to unverified lists with high bounce rates
- Using heavy HTML, images and tracked links in cold emails
- Sending the same template to everyone
Check the result
Warmup is only working if your real emails land in the inbox. Run an inbox placement test before each new campaign and after any change in volume.
Questions
How long does email warmup take?
Two to three weeks for a new mailbox is typical before it reaches full cold email volume.
Should warmup keep running after the mailbox is warm?
Many senders keep a low level of warmup running alongside campaigns to keep the pattern of positive engagement steady.
Does Coldvane include warmup?
Yes. Warmup and inbox placement tests are included from the Growth plan.