A brand-new mailbox has no sending history. Receiving providers treat unknown senders that suddenly send hundreds of cold emails as suspicious, and place them accordingly.
What warmup does
Warmup sends a small, gradually increasing volume of conversational mail from your mailbox and generates natural engagement with it — opens and replies — so the mailbox builds a track record before it carries campaign traffic.
What to expect
- Volume ramps over weeks, not days
- Campaign capacity stays low while a mailbox is Warming
- Health improves gradually and can regress if you push volume too hard
Important notes
Warmup is not a workaround for bad list quality. It builds reputation; sending to invalid or uninterested addresses destroys it faster than warmup can rebuild it.
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