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Mailboxes
Mailboxes: Create, Manage, and Organize Senders
Understand what a mailbox represents in Cold Mail Server and how to use mailbox boundaries to organize sender identity, access, and operations.
Audience: All customersTime: 10-15 minutes
Updated April 2026
Before you begin
- At least one verified domain
Table of contents
1) What a mailbox is (and is not)
A mailbox is a sender identity unit, not just a row in a table.
- Each mailbox maps to a sending identity (for example, a rep, inbox, or campaign persona).
- Auth keys are issued per mailbox, so credentials can be isolated by sender context.
- Mailbox status determines whether that identity can currently send.
- Using separate mailboxes prevents one sender workflow from impacting all traffic.
2) Create mailboxes
Mailbox setup is fast once a domain is verified.
- Open Mailboxes and click Add Mailbox.
- Enter mailbox name and select domain.
- Save and confirm mailbox appears as active.
- Use clear naming to identify campaign purpose.
3) Manage active and inactive mailboxes
Use status toggles to control sender availability.
- Deactivate mailboxes not currently used.
- Reactivate when campaigns resume.
- Filter mailboxes by domain for easier management.
- Review mailbox list regularly for cleanup.