Domain Warm-up
Gradually ramping sending volume on a new domain or inbox so mailbox providers see a normal sender, not a sudden blaster.
Warm-up is the process of slowly increasing email volume over three to four weeks on a fresh domain or inbox, so providers build trust instead of flagging a cold domain that suddenly sends hundreds of messages.
It's why cold email scales horizontally — across many warmed inboxes — rather than by pushing more volume through one. Skipping warm-up is one of the fastest ways to land a new domain in spam.
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