Create one in Agents & MCP

Give this agent an inbox creates an address on the platform domain (by default agents.sendwithflare.com). The local part is lowercase, unique, and reserved names are blocked.

Receive, MCP, and the developer API use the same mailbox as a custom-domain address. Sending stays off until the platform outbound provider is configured. The screen does not say ready to send until that is true.

Use your own domain

A paying customer who wants every address at their own domain, such as [email protected], adds that root domain in Sending domains. The domain must already be an active Cloudflare zone. FlareMail then enables the catch-all, so agent mail and human mail on that domain arrive in the same account. Scope the Agent Key to the mailbox the agent should use.

That catch-all works because theirdomain.com is the zone itself. A name underneath it, such as agents.theirdomain.com, cannot be a separate zone on a Free, Pro, or Business account, and Email Routing will not catch every address on that subdomain. Put the agent address on the root domain.