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.
- - Zimbra Collaboration Suite is the most popular Web-based, Linux & Self-Hosted alternative to Sendmail.
- - Zimbra Collaboration Suite is the most popular Open Source & free alternative to Sendmail.
Zentyal is a native Microsoft Active Directory implementation on Linux incorporating all the network services required in a small and medium business environment: Directory & Domain Server, Mail Server, Gateway and Infrastructure Server.
- - Zentyal is the most popular commercial alternative to Sendmail.
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.
- - Postfix is the most popular Mac alternative to Sendmail.
Opinions about Postfix as a Alternative to Sendmail
Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the Microsoft Servers line of server products and is widely used by enterprises using Microsoft infrastructure solutions.
- - Microsoft Exchange Server is the most popular Windows alternative to Sendmail.
Microsoft Exchange Server Features
OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with some additional standard extensions. It allows ordinary machines to exchange e-mails with other systems speaking the SMTP protocol.
sSMTP is a simple MTA to deliver mail from a computer to a mail server. sSMTP is simple and lightweight, there are no daemons or anything hogging up CPU; Just sSMTP. Unlike Exim4, sSMTP does not receive mail, expand aliases, or manage a queue.Discontinued
The last update was in 2013.
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.
Atmail Email Server Features
A small Mail Transport Agent (MTA), designed for home and office use. Part of DragonFly BSD , it accepts mails from locally installed Mail User Agents (MUA) and delivers the mails either locally or to a remote destination.
Dragonfly Mail Agent Features