Send Gmail Message
send_gmail_messageSend Gmail emails immediately from an authenticated account, including new messages, replies, forwards, CC/BCC, attachments, and configured Send As aliases.
Instructions
Sends an email using the user's Gmail account. Supports new emails, replies, and forwards, with optional attachments. Supports Gmail's "Send As" feature to send from configured alias addresses.
To forward an existing message, pass forward_message_id. The original subject, body (quoted with a "Forwarded message" header), and attachments are carried over. In forward mode, body (if any) is prepended as a note and subject is optional. Threading, reply, and signature options do not apply when forwarding.
THIS TOOL SENDS IMMEDIATELY AND CANNOT SCHEDULE. Gmail's REST API exposes no send-time parameter; Schedule send is a web-UI feature with no API equivalent, so no argument to this tool can defer delivery. Never tell a user a message was scheduled. For "prepare now, deliver later", create a draft with draft_gmail_message. An external scheduler must retain the message data to create and send a new message via send_gmail_message at the chosen time, or call users.drafts.send with the draft ID returned by draft_gmail_message. Alternatively, let the user schedule that draft in the Gmail UI.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cc | No | Optional CC email address. | |
| to | No | Recipient email address. Optional when replying with reply_all=True, which derives it from the thread. | |
| bcc | No | Optional BCC email address. | |
| body | No | Email body content (plain text or HTML). Required when sending. When forwarding, this is an optional note prepended above the quoted original. | |
| subject | No | Email subject. Required for a new message. Optional when replying with thread_id (inherits the parent message's subject, adding 'Re:' only if absent) or when forwarding (defaults to 'Fwd: <original subject>'). | |
| direction | No | Base text direction of the body. 'auto' (default) takes it from the first strong character (a right-to-left script gives 'rtl', anything else 'ltr'); 'ltr'/'rtl' force it. On a forward it orients the note. | auto |
| from_name | No | Optional sender display name (e.g., 'Peter Hartree'). If provided, the From header will be formatted as 'Name <email>'. | |
| reply_all | No | Whether to derive reply-all recipients from the thread: To = the sender being replied to, Cc = the other participants, excluding the authenticated account and from_email. Requires thread_id. Explicit to/cc win; when cc is omitted the sender being replied to is added to the derived Cc if they are not already in To. Defaults to false. | |
| thread_id | No | Optional Gmail thread ID to reply within. When in_reply_to is omitted, replies to the latest non-draft, non-trash message with an RFC Message-ID. | |
| from_email | No | Optional 'Send As' alias email address. Must be configured in Gmail settings (Settings > Accounts > Send mail as). If not provided, uses the authenticated user's email. | |
| references | No | Optional Message-ID ancestry chain. Normally omit when thread_id is provided; the server derives the chain through the selected reply target. | |
| attachments | No | Optional list of attachments. Each can have: "url" (fetch from URL — works with MCP attachment URLs from get_drive_file_download_url / get_gmail_attachment_content), OR "path" (file path, auto-encodes), OR "content" (standard base64, not urlsafe) + "filename". Optional "mime_type". Optional "content_id" (string) makes the attachment inline-rendered: it lands in a multipart/related part with `Content-ID: <content_id>` and `Content-Disposition: inline`, and the HTML body can reference it via `<img src="cid:<content_id>">` (RFC 2392). Without `content_id` the attachment is a regular multipart/mixed attachment. Example: [{"url": "https://host/attachments/abc-123", "filename": "report.pdf"}] | |
| body_format | No | Format of the body content (and of the prepended note when forwarding). Use 'plain' for plaintext or 'html' for HTML content. With 'html', write real markup; an entity-escaped body ('<div>') is rejected. | plain |
| in_reply_to | No | Optional RFC Message-ID to explicitly reply to a specific message (e.g., '<message123@gmail.com>'). Omit to reply to the latest eligible message in thread_id. | |
| quote_original | No | Whether to include the message being replied to as a quoted original. Only has an effect when thread_id is provided. Defaults to false. | |
| include_signature | No | Whether to append the Gmail signature from Settings > Signature when available. Defaults to true. | |
| user_google_email | Yes | The user's Google email address. Required for authentication. | |
| forward_message_id | No | Set to a Gmail message ID to forward that message instead of composing a new one. The original subject, body, and (optionally) attachments are carried over; 'body' becomes an optional note prepended to the forward. | |
| include_forwarded_attachments | No | When forwarding, whether to include the original message's attachments. Ignored unless forward_message_id is set. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |