Postfix logo

Postfix

Website

Secure and efficient SMTP mail transfer agent (MTA)

Activity unknown

No repository statistics available for this project.

Postfix screenshot

Postfix is an SMTP mail transfer agent (MTA) used to send, receive, and route email between mail servers and local delivery services. Originally developed by Wietse Venema as an alternative to Sendmail, it is designed to be fast, secure, and straightforward to administer on Unix-like systems.

Key Features

  • SMTP server and mail relay capabilities for inbound and outbound mail flow
  • Queue management for reliable delivery and handling of transient failures
  • Flexible routing and policy controls (transports, relaying rules, restrictions)
  • Pluggable integrations for authentication, filtering, and content scanning via common mail workflows
  • Support for modern operational needs such as TLS-encrypted SMTP and extensive logging

Use Cases

  • Running an organization’s primary mail transfer agent for SMTP delivery
  • Operating a secure outbound relay (smart host) for applications and servers
  • Building a mail gateway in front of internal mailboxes with filtering and routing rules

Limitations and Considerations

  • Postfix is an MTA, not a full groupware or webmail solution; mailbox access typically requires separate IMAP/POP and webmail components
  • Advanced features (spam filtering, DKIM/DMARC, antivirus, mailbox storage) usually rely on integrating additional services

Postfix remains a widely deployed choice for SMTP delivery thanks to its security-focused design and mature operational tooling. It fits both small deployments and high-volume mail infrastructure when combined with appropriate mailbox and filtering components.

Categories:

Tags:

Tech Stack:

Share:

Similar to Postfix

OpenSMTPD logo

OpenSMTPD

Secure, lightweight SMTP server implementation compliant with RFC 5321

OpenSMTPD is an open-source, minimal SMTP daemon from the OpenBSD project providing an RFC-compliant MTA with privilege separation, table backends, filters and TLS support.

Activity unknown
Alternative to:
Postfix logo
Postfix
+11
Exim logo

Exim

Configurable SMTP message transfer agent for Unix-like systems

Exim is an open source SMTP message transfer agent (MTA) for Unix-like systems, offering flexible mail routing and extensive controls for handling inbound email.

Activity unknown
Alternative to:
Amazon Simple Email Service (Amazon SES) logo
Amazon Simple Email Service (Amazon SES)
+10
Dovel logo

Dovel

Simple Go-based SMTP server for receiving and sending mail

Lightweight SMTP server written in Go that receives and sends email via a single JSON config and executable hooks; supports per-user DKIM and TLS.

Activity unknown
Alternative to:
Amazon Simple Email Service (Amazon SES) logo
Amazon Simple Email Service (Amazon SES)
+11
Sendmail Open Source logo

Sendmail Open Source

Open source subset of Sendmail Sentrion for enterprise email environments.

Open Source Sendmail provides a subset of Proofpoint's Sendmail Sentrion MTA for large-scale mail deployments; current release is 8.16.1 with a PGP-signed tarball and OpenDKIM integration.

Activity unknown
Alternative to:
Postfix logo
Postfix
+12
Courier Mail Server (Courier MTA) logo

Courier Mail Server (Courier MTA)

Integrated mail server suite with SMTP, IMAP, POP3 and webmail

Courier is an integrated mail server suite providing ESMTP (MTA), IMAP, POP3, webmail, and mailing lists with optional LDAP/MySQL/PostgreSQL-backed virtual accounts.

Activity unknown
Alternative to:
Microsoft Exchange Online logo
Microsoft Exchange Online
+14
Postal logo

Postal

Open source mail delivery platform for inbound and outbound email

16.8k
1.3k
Last commit

Postal is an open source mail delivery platform for sending and receiving email, with SMTP support, web-based management, and tools for running your own SendGrid-style service.

MITActively maintained
Alternative to:
SendGrid logo
SendGrid
+10