Postfix

Postfix SMTP

Postfix implements SMTP (RFC 5321) for sending and receiving electronic mail, with submission (port 587), SMTPS (port 465), and standard SMTP (port 25) endpoints. There is no public HTTP/REST API; integration is via SMTP protocol, configuration files, milter (mail filter) hooks, and policy daemons.

GitHub

Documentation

📖
Documentation
https://www.postfix.org/documentation.html

Other Resources

🔗
SMTP Specification
https://datatracker.ietf.org/doc/html/rfc5321
🔗
Configuration Reference
https://www.postfix.org/postconf.5.html
🔗
Milter Protocol
https://www.postfix.org/MILTER_README.html
🔗
APIsJSON
https://raw.githubusercontent.com/api-evangelist/postfix/refs/heads/main/apis.yml

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API entry from apis.yml

apis.yml Raw ↑ 
aid: postfix:smtp
name: Postfix SMTP
description: Postfix implements SMTP (RFC 5321) for sending and receiving electronic mail, with submission
  (port 587), SMTPS (port 465), and standard SMTP (port 25) endpoints. There is no public HTTP/REST API;
  integration is via SMTP protocol, configuration files, milter (mail filter) hooks, and policy daemons.
humanURL: https://www.postfix.org/documentation.html
baseURL: smtp://localhost:25
tags:
- SMTP
- Email
- Mail Server
- Protocol
properties:
- type: Documentation
  url: https://www.postfix.org/documentation.html
- type: SMTP Specification
  url: https://datatracker.ietf.org/doc/html/rfc5321
- type: Configuration Reference
  url: https://www.postfix.org/postconf.5.html
- type: Milter Protocol
  url: https://www.postfix.org/MILTER_README.html