| Feature | Postfix | Exim | Sendmail | hMailServer | iRedMail | Docker Mailserver | Mailu | Chasquid | Apache James | |—|—|—|—|—|—|—|—|—| | Anti-spam | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | System requirements | Low | Low | Low | Low | Medium | Low | Low | Low | Low | | Windows/Linux | Both | Both | Both | Windows | Linux | Both | Linux | Linux | Both | | Average reviews | Good | Good | Good | Good | Good | Good | Good | Good | Good | | API support | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | POP3, SMTP, IMAP | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Virtual domains | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Built-in backup | No | No | No | Yes | Yes | No | Yes | No | No | | SSL encryption | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Anti-virus | No | No | No | Yes | Yes | No | Yes | No | No | | Scripting | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Server-side rules | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Multilingual | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Routing | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | MX backup | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | Multihoming | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | | SQL backend | No | No | No | Yes | Yes | No | Yes | No | Yes | | Web administration | No | No | No | Yes | Yes | No | Yes | No | Yes |
