What is email warmup?
In short
Email warmup is the practice of gradually increasing sending volume from a new domain or mailbox so that mailbox providers learn to trust it.
The definition
Warmup means starting small and building up. A new domain sends a handful of messages a day, then more, over roughly two weeks, until the volume you actually need looks normal for that sender.
The purpose is reputation. Mailbox providers judge senders on history, and a domain with no history that suddenly sends hundreds of messages looks exactly like a compromised account.
How long it takes
About two weeks before running a real campaign. There is no way to buy the time back, which is why outbound programmes go live in week three rather than week one.
Warming continues quietly after that. A domain that sends consistently keeps its reputation; one that goes silent for a month and then resumes at full volume looks new again.
What happens if you skip it
Placement collapses. The messages are accepted and filed in spam, so open rates look plausible while nothing is being read.
Worse, the damage attaches to the domain. If that domain is the one your invoices and support replies come from, you have traded a sales channel for an operational one.
Automated warmup tools
Most sending platforms include one. They exchange messages between mailboxes to simulate engagement, which helps, and is not a substitute for sending relevant mail to real people who want it.
Warmup gets you delivered. It does not make anyone reply.
Frequently asked
What is email warmup?
How long does email warmup take?
What happens if I skip warmup?
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