Shared company mailbox for one agent
One company address like hello@ owned by one agent: an API inbox, message.received webhook, thread object, stable message ids, and replies from the same address.
The problem
Gmail IMAP and Gmail API need a human OAuth seat.
Microsoft Graph and Outlook shared mailboxes use human tenant OAuth.
Postmark Inbound is a webhook parse pipe, not an agent-owned mailbox.
Resend Receiving notifies via webhook around inbound parse and reply.
Front gives humans a triage UI without an agent-owned address.
The solution
AgentMail is the mailbox layer for one company address owned by one agent. You do not need a domain per agent or a fleet to start.
One inbox for hello@ or a forward
Create an AgentMail inbox, or forward hello@ into it.
message.received with thread_id
A POST delivers parsed mail with thread_id, not an IMAP poll.
Stable message_id for idempotency
Dedupe on message_id when a webhook retries.
Reply from the same inbox as hello@
messages.reply answers as the company address.
What your shared-inbox agent can do
Triage
Classify and route hello@
Read from_, subject, and text, then label or hand off.
Reply
Reply in the same thread
messages.reply keeps the customer in the same thread.
Idempotency
Idempotent handlers on message_id
Store processed message_id values before side effects.
Handoff
Forward or escalate
Escalate from the same inbox when a human needs the thread.
AgentMail is built to scale.
Redundant infrastructure spanning multiple regions, so a message to your agent lands even when a region does not.
Provision an inbox in milliseconds. Nothing to verify, nothing to wait on.
Typed SDKs, REST endpoints, and webhooks. Your first send goes out the same afternoon.
Wire the shared-inbox webhook
Create the inbox, subscribe to message.received, return 200, then reply on the same inbox_id.
FAQ
Common questions about AgentMail and shared company mailbox for one agent.
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