Send Gmail Message
send_gmail_messageSend, reply, or forward Gmail emails with attachments, aliases, and threading support.
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.
Input Schema
TableJSON 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 when sending; optional when forwarding (defaults to 'Fwd: <original subject>'). | |
| 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. | |
| 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 chain of Message-IDs for proper threading. | |
| 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. | plain |
| in_reply_to | No | Optional RFC Message-ID of the message being replied to (e.g., '<message123@gmail.com>'). | |
| 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
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |