Inbox rotation (or mailbox rotation) spreads a campaign across several sending mailboxes instead of sending everything from one. Each lead is assigned a mailbox, and every mailbox sends only its own small daily share.
Why it matters
One mailbox should send only around 30 cold emails a day. Reaching 3,000 people a week means many mailboxes, and rotation is what lets a single campaign use them all while keeping each one's volume safe.
How it should work
- A lead keeps one mailbox: the first email and every follow-up come from the same sender, in the same thread.
- Healthy mailboxes first: a mailbox whose bounces or spam rate climb sends less, or rests.
- Provider matching: Gmail recipients from Google mailboxes where you have them.
- Even pacing: each mailbox's emails spread across the working day.
mailzy rotates campaigns this way by default. Work out how many mailboxes a goal needs with the free mailbox calculator.