Gate modes

Every send, reply and forward goes to a gate that runs on the server. The agent does not decide, and nothing written in an email can change the outcome. Each answer is sent, held or an error with a reason.

A held message waits in Review. You can edit it, approve it or reject it. The agent is told not to send it again. After you approve, there are five seconds to press Undo before it goes. An agent can also save a draft with mail_draft, which sends nothing and waits the same way.

The three modes

A person sets a mailbox's mode and allow list in the dashboard. The agent can read them with mail_rules and cannot change them.

• review holds every message. It is the only mode on Free.
• filtered sends a message in a conversation a person started, or only to addresses on the allow list. It holds attachments and flagged threads, and anything no rule covers.
• none sends unless one of the always held cases below applies. It needs Team.

If a plan change leaves a mailbox in a mode the plan no longer has, the mailbox drops to the nearest allowed mode that is no more permissive. If there is none, sends are refused.

Always held, in every mode

• The first message to an address that has never written to the workspace, unless a person put that address or its domain on the allow list.
• A reply to machine mail: autoresponders, lists and bulk mail.
• A reply to a message whose sender failed DMARC alignment, because its From address may be forged.

Refused

Limits refuse a message instead of holding it: no recipients, a mode the plan does not allow, an attachment over the plan's size, and the daily and monthly send limits. See Plans and limits.

Reason	What it means	Outcome
review_mode	This mailbox reviews every message.	Held for a person
first_contact	First message to an address that has never written to this workspace.	Held for a person
replying_to_machine	It answers an automatic or list message, which Mail never replies to on its own.	Held for a person
unauthenticated_sender	It answers a message whose sender could not be verified, so the From address may be forged.	Held for a person
draft	The agent saved this as a draft rather than sending it.	Held for a person
attachment	It carries an attachment.	Held for a person
thread_flagged	Screening flagged something in this thread.	Held for a person
no_send_rule	No rule lets this message go without a person.	Held for a person
no_recipients	It has no recipients.	Refused
mode_not_allowed	The mailbox’s mode is not part of the workspace’s plan.	Refused
attachment_cap	An attachment is over the plan’s size limit.	Refused
daily_cap	The workspace reached today’s send limit.	Refused
monthly_cap	The workspace used this month’s sends.	Refused

Every message that goes out ends with a line saying an AI agent sent it.