A brand new mailbox or domain has no history. If it starts sending hundreds of cold emails on day one, providers treat it like a spammer. Warmup tools solve this by trading emails with a pool of other mailboxes that open them, reply and rescue any that land in spam, while the volume rises a little each day.
Week 1 to 3: warmup only, rising to about 20 warmup emails a day. Week 4: about 5 cold emails a day per mailbox. Week 5: 10. Week 6: 15. Week 7 on: 20, the recommended most.
How long it takes
Plan on about three weeks before the first cold email. In ZicReach, a mailbox shows as Warming up from day 7, Almost warmed up from day 10 and Warmed up from day 21, and warmup keeps running in the background after you start sending. The warmup schedule planner turns your target volume into a week by week plan.
What warmup cannot fix
- A bad list. Bounces and spam traps undo warmup quickly; verify addresses first.
- Missing authentication. Warm a mailbox only after SPF, DKIM and DMARC pass.
- Copy that reads like spam. Check it with the spam word checker before you send.
- Too much volume. Past about 20 cold emails a day per mailbox, add mailboxes instead.
In ZicReach, email warmup is free and unlimited on every plan, the free plan included. A health score watches each mailbox, and campaigns stop using a mailbox whose health falls below your limit while warmup keeps going until it recovers. Read more in how long to warm up an email domain.