Agent Mailboxes: programmable two-way email for AI agents

Agent Mailboxes give your AI agents a durable email address they can own, read, and reply from. Every inbound message lands in a conversation thread with parsed body text and attachment metadata; your agent reads it and replies in one API call. No mail server to run, no domain to verify.

Claim an address. Omit the local part and Bird generates a unique address (abc123@inbox.ai) at no extra cost. On paid plans you can choose your own handle (support@inbox.ai) up to your plan's allowance, or use your own inbound-enabled domain. Each mailbox has a receive policy (open, replies_only, allowlist, drop), per-sender allow/block rules, and a 30-day retention window.

Read conversations. Inbound mail groups into threads automatically. Each message carries quote-stripped extracted_text — the new content only, without the history your agent would otherwise have to parse. Threads have placement labels (inbox, archive, spam, blocked, plus any custom label), unread state, and a last_direction field so your agent always knows whether the last move was theirs.

Reply and compose. Reply to a message in one call — the reply folds into the existing thread and sends from the mailbox address. To start a fresh outbound conversation, compose from the mailbox; the response carries a thread ID for tracking replies.

Webhooks. Subscribe to email_mailbox.message_received, email_mailbox.thread_created, email_mailbox.message_sent, email_mailbox.message_delivered, and email_mailbox.message_failed. Only inbox-placement mail fires webhooks — spam and blocked mail is stored silently.

Available on every surface

Surface	How to use
REST API	/v1/email/mailboxes + /v1/email/threads — new mailbox and mailbox_management API key scopes
TypeScript SDK	bird.mailbox, bird.mailboxThread, bird.mailboxThreadMessage
Python SDK	client.mailbox, client.mailbox_thread, client.mailbox_thread_message
Go SDK	client.Mailbox, client.MailboxThread, client.MailboxThreadMessage
CLI	bird email mailboxes · bird email threads · bird email threads messages
MCP	Full tool set — email_mailboxes_*, email_threads_*, email_threads_messages_*

Getting started

Create an API key in the dashboard — under the Email group, enable the mailbox scope, then follow the Agent Mailboxes quickstart to claim an address, receive your first message, and send a reply in under five minutes.

Full API reference, receive rules, retention, and webhook payloads: Agent Mailboxes guide.