Enhanced n8n EmailSend Node

An enhanced version of the n8n EmailSend node that includes email threading support through inReplyTo and references headers.

Features

• Email Threading Support: Properly handle email conversations with inReplyTo and references headers
• SMTP Protocol: Full SMTP support with authentication
• Attachments: Support for email attachments
• Multiple Recipients: CC and BCC support
• Priority Settings: Set email priority (low, normal, high)
• HTML and Text: Support for both HTML and plain text emails

New Fields

In-Reply-To

• Field Name: inReplyTo
• Type: String
• Description: Message ID of the email this is a reply to
• Example: <original-message-id@example.com>
• Usage: Used by email clients to thread conversations properly

References

• Field Name: references
• Type: String
• Description: Space or comma-separated list of message IDs in the conversation thread
• Example: <original-message-id@example.com> <another-message-id@example.com>
• Usage: Maintains the complete conversation thread for email clients

SMTP Standards Compliance

These fields follow RFC 5322 standards for email threading:

• In-Reply-To: Contains the message ID of the email being replied to
• References: Contains all message IDs in the conversation thread, allowing email clients to properly group related emails

Installation

1. Build the project:

   npm run build
   

2. Copy the built files to your n8n custom nodes directory

3. Restart your n8n instance

Usage

1. Add the "Send Email" node to your workflow
2. Configure SMTP credentials
3. Fill in the basic email fields (from, to, subject, text/html)
4. In "Additional Fields":
   • Add inReplyTo with the message ID you're replying to
   • Add references with the conversation thread message IDs
5. Execute the workflow

Example

{
  "inReplyTo": "<original-message-id@example.com>",
  "references": "<original-message-id@example.com> <previous-message-id@example.com>"
}

This ensures proper email threading in email clients like Gmail, Outlook, and Thunderbird.