Compare Postfix vs. Zimbra vs. hMailServer

Postfix is a mail server developed by Wietse Venema, originally created at IBM research as a viable alternative to the popular Sendmail program, and Wietse continues to enhance and maintain it while working at Google. This robust mail server operates on various UNIX systems including AIX, BSD, HP-UX, IRIX, LINUX, MacOS X, Solaris, and Tru64 UNIX, requiring ANSI C, a POSIX.1 library, and BSD sockets for its functionality. Designed with speed, ease of administration, and security in mind, Postfix features an exterior reminiscent of Sendmail, yet its internal architecture is entirely distinct. Among its key capabilities are the support for multiple SMTP deliveries over a single TLS-encrypted connection, leveraging the existing tlsproxy(8) and scache(8) services, as well as the ability to utilize MySQL stored procedures. Moreover, Postfix implements a gradual degradation feature, allowing a daemon to log warnings and continue operation despite encountering some service issues, rather than terminating abruptly with a fatal error. Additionally, it can set the execute bit on a queue file, which is critical, as failure to do so would prevent any mail from being delivered successfully. This combination of features makes Postfix a versatile choice for mail server management.

Zimbra 9: Collaboration Superheroes! Users can seamlessly switch between desktop, tablet, and mobile browsers while enjoying consistent email and collaboration experiences. It is extensible and offers best-in-class integrations with Slack and Dropbox. There are many more in development. Zimlet framework allows you to customize Zimbra according to your needs. Zimbra's reliable server infrastructure ensures that customers have the security, privacy, and data sovereignty they expect. Upgrade to Zimbra 9 is easy and requires no data migration. Zimbra 9's responsive, modern UI is built on Zimbra’s reliable server infrastructure. This ensures the security, privacy, and data sovereignty that you have come to expect from Zimbra. Zimbra 9 is flexible, extensible and unlike competitors that use closed platforms. Get out of Microsoft and Google and integrate with third-party collaboration services such as Dropbox, Zoom, and Slack.

hMailServer is a complimentary and open-source email server designed for the Microsoft Windows platform. It is utilized globally by various entities, including internet service providers, businesses, governmental organizations, educational institutions, and individual users with a passion for technology. The server accommodates standard email protocols such as IMAP, SMTP, and POP3, making it compatible with numerous existing webmail systems. Additionally, it features a customizable score-based spam protection system and can be integrated with virus scanners to ensure that all incoming and outgoing emails are thoroughly checked for threats. This versatility makes hMailServer a popular choice for those seeking a reliable email solution.