$ man inbox-setup

Email Infrastructure · Infrastructure Basics

Inbox Setup

The process of creating sending mailboxes on secondary domains. Each mailbox is a "from" address — the identity that sends the email. john@acme-team.com, sarah@tryacme.io.

why it matters

You can't send from a domain alone. You need mailboxes. Each mailbox has its own reputation, its own sending limits, and its own warmup timeline. The number of mailboxes you set up determines your total daily sending capacity. Too few and you can't reach enough people. Too many without proper warmup and you burn them all.

how I use it

I set up mailboxes through the inbox provider — Google Workspace or Microsoft 365 — on each secondary domain. Each mailbox gets a real-looking name (not noreply@). I configure display names, profile photos when possible, and email signatures. Then each mailbox goes into the sending platform (Instantly) for warmup. I don't send real campaigns from a mailbox until it's been warming for at least 2 weeks.

related terms

Secondary Domains

go deeper

✉Email Infrastructure Guide →

content playbooks

♢X Algorithm Deep Dive →♢X Format and Growth Guide →

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