Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail. It attempts to be fast, easy to administer, and secure. The software is also known by its former names VMailer and IBM Secure Mailer.

EmailSuccess is described as 'An advanced SMTP Server (MTA) built from the ground up to handle the most critical reliability, performance, security, and deliverability requirements' and is a Mail Server in the online services category. There are more than 10 alternatives to EmailSuccess for a variety of platforms, including Linux, Mac, Self-Hosted, Windows and Web-based apps. The best EmailSuccess alternative is Postfix, which is both free and Open Source. Other great apps like EmailSuccess are Zentyal, Zimbra Collaboration Suite, hMail Server and Microsoft Exchange.
Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail. It attempts to be fast, easy to administer, and secure. The software is also known by its former names VMailer and IBM Secure Mailer.

Integrates native Active Directory and all essential network services, including domain, mail, gateway, infrastructure, and security roles, for SMBs, offering web-based management, centralized authentication, file server, VPN, and firewall in a single Linux platform.




Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more. With the most innovative web application available today, Zimbra boosts the productivity of users on any desktop and dramatically reduces TCO compared to legacy platform vendors.

hMailServer is a free e-mail server for Microsoft Windows. Its used by Internet service providers, companies, governments, schools and enthusiasts in all parts of the world.


Exchange business-class email helps increase user productivity while protecting your data. Get it as a hosted service or run it on your servers.




KumoMTA is the only true Open-Source PowerMTA alternative, capable of matching performance of several million messages per hour while providing granular traffic shaping configuration and automation across unlimited IPs.

SmarterMail is the only other email server on the market with native support for MAPI, the protocol that powers Exchange and Outlook. That means anything you can do on Exchange you can do with SmarterMail: no plug-ins and no additional software required.




Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.
Real-time email, chat, audio/video calls & conferences, file-sharing, and contacts app with a modern and intuitive UI.




Sendmail is a general purpose internetwork email routing facility that supports many kinds of transfer and delivery methods, including the Simple Mail Transfer Protocol (SMTP) used for email transport over the Internet.

The Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols, such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, webmail, and mailing list services within a single, consistent, framework.
Atmail webmail system offers a webmail client, email server platform and mailserver appliance for Linux, Unix and Windows.


