Mailboxes
Create company addresses and choose who can read, send, and manage each one.
Create a mailbox
A mailbox needs a verified domain. In Settings → Inboxes, choose Add inbox, then provide:
- Address — the local part before
@, such ashelloorfounder. - Display name — the human-readable sender name recipients see.
- Visibility — shared or private.
The local part can contain letters, numbers, dots, dashes, and underscores. It must be unique on the selected domain.
Shared mailboxes
Every workspace member can read a shared mailbox. People who can use it may reply and compose from its address. Shared mailboxes work well for hello@, support@, or another address handled by the team.
Private mailboxes
A private mailbox belongs to an owner. Its messages and attachments are visible only to that owner and people granted explicit access. A grant can include read-only or read-and-send permission.
Mailbox access in developer tools
API keys and MCP connections see only mailboxes available to the identity behind the key. Scope still applies: mailboxes:read lists mailbox metadata, mail:read exposes threads, and mail:send permits sending from a mailbox where the identity can send.
Address lifecycle
Mailbox addresses are durable identities. Treat renaming or moving an address as a migration: tell correspondents, update automated integrations, and test replies. Startup Mail does not provide catch-all routing.