Why an AI agent needs its own inbox, not a shared mailbox

Description and use

Each AI agent gets its own inbox to prevent duplicate replies and keep read state server‑side.

Problem

Agents sharing a mailbox can mark each other’s messages as read, causing duplicate replies and loss of message state.

Outcome

Dedicated inboxes per agent eliminate duplicate replies, preserve threading, and simplify cleanup.

Workflow

• Assign a unique email address to each agent.
• Configure the agent to fetch only unread messages for its address.
• Process messages and reply, letting the server mark them as read.
• If the agent crashes, the message remains unread for retry.
• Delete the agent’s mailbox when the agent is removed.
• Use stable message IDs to deduplicate across restarts and workers.

Evidence

Most teams wiring an agent into email give it the same mailbox the humans use.

Source

The fix is boring and structural: give every agent its own address.

Source

Store the message id, not the sequence number. Sequence numbers shift when a message is expunged; a stable id lets the agent deduplicate across restarts and across two workers running the same job.

Source