Send Email with Threading

Sends an email using SMTP protocol with reply threading support

Send

AI-generated

Overview

This node sends emails using the SMTP protocol with support for email threading features such as "In-Reply-To" and "References" headers. It is useful in scenarios where automated email sending is required, including sending notifications, alerts, or follow-up emails that maintain conversation context.

Practical examples:

  • Sending a notification email to users after a form submission.
  • Sending marketing emails with CC and BCC recipients.
  • Replying to an existing email thread programmatically by setting appropriate headers.
  • Attaching files stored in binary data properties to outgoing emails.

Properties

Name Meaning
From Email Email address of the sender.
To Email Email address(es) of the recipient(s). Multiple addresses can be separated by commas.
Subject Subject line of the email.
Text Plain text content of the email message.
HTML HTML content of the email message.
Additional Fields Collection of optional fields:
- Attachments: Names of binary properties containing attachments (comma-separated).
- BCC Email: Blind copy recipient email(s), comma-separated.
- CC Email: Copy recipient email(s), comma-separated.
- In-Reply-To: Message ID this email replies to (for threading).
- Priority: Email priority; options are Low, Normal, High.
- References: Message IDs in the conversation thread (space or comma-separated).
- Reply To: Email address for replies.

Output

The node outputs a JSON object per input item containing:

  • messageId: The unique identifier of the sent email message.
  • accepted: List of accepted recipient addresses.
  • rejected: List of rejected recipient addresses.
  • response: Raw response from the SMTP server.

If sending fails and "Continue On Fail" is enabled, the output will contain an error field with the error message instead.

Dependencies

  • Requires an SMTP server credential configured in n8n to send emails.
  • Uses the SMTP protocol via a transporter created internally.
  • Binary data attachments must be provided in the input items under specified property names.

Troubleshooting

  • Common issues:

    • Invalid SMTP credentials or connection failure to the SMTP server.
    • Incorrectly formatted email addresses causing rejection.
    • Missing required fields like "From Email" or "To Email".
    • Attachment property names not matching any binary data in the input.

  • Error messages:

    • Errors thrown by the SMTP server (e.g., authentication errors, connection timeouts) will appear in the node's error output.
    • If "Continue On Fail" is disabled, the node execution stops on the first error.

  • Resolutions:

    • Verify SMTP credentials and server accessibility.
    • Ensure all email addresses are valid and properly formatted.
    • Confirm that attachment property names correspond exactly to binary data keys in the input.
    • Use "Continue On Fail" option to handle partial failures gracefully.

Links and References

Discussion