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Replies to a message and sends the reply immediately. This delivers mail to the recipients and cannot be undone. Use it when the user has already asked for the reply to be sent. To stage a reply for review instead, use create_draft with inReplyTo — same threading, no delivery. The recipients, the Re: subject, and the In-Reply-To/References headers all come from the original message. The reply is written into Drafts first and only then submitted, so a submission that fails leaves a recoverable draft rather than nothing at all.

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Parameters

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string
required
Id of the message being replied to, as returned by search_emails or get_thread.
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string
Plain-text body of the reply. Either text or html (or both) is required.
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string
HTML body of the reply.
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boolean
Reply to everyone: the original’s To and Cc are added to Cc, minus the user themselves. Cannot be combined with to, cc, or bcc.
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string[]
Override the recipients instead of deriving them from the original. Cannot be combined with replyAll.
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string[]
Override the carbon-copy recipients. Cannot be combined with replyAll.
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string[]
Blind-copy recipients. Cannot be combined with replyAll.
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string
Override the subject. Defaults to Re: <original subject>.
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string
Client-chosen key that makes the call safe to retry: a repeat with the same key returns the first call’s answer instead of sending a second reply. Keys are scoped to the account and to this tool. Remembered for 15 minutes.

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Example

Call
Result

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Notes

  • replyAll and explicit recipients are mutually exclusive, and the conflict is rejected rather than resolved. “Reply to everyone, but only these people” has no defensible reading, and silently picking one is how an agent mails the wrong list.
  • The original is not quoted into the reply. Include any context the recipient needs in text.
  • Every address the account can send as is excluded from the reply’s recipients, not just the one it is going out as — a message addressed to one of the user’s aliases does not put that alias on the reply.
  • The reply always goes out from the account’s own address. To reply from an alias, use create_draft with from and then send_draft.
  • Attachments cannot be added here. This tool stages and sends in one call, so there is no point to inspect what is attached before it goes out. To reply with a file, use create_draft with inReplyTo and attachments, then send_draft.
  • The reply is written into Drafts before it is submitted, so a submission that fails leaves a recoverable draft — the error names its id.

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Errors

  • replyAll cannot be combined with to/cc/bcc. … Nothing was sent.
  • Provide a body: text, html, or both.
  • Cannot reply: message not found: <id>. Nothing was sent.
  • Cannot reply: <id> has no sender address to reply to. Pass to explicitly. Nothing was sent.