Postfix - Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.
Inbucket - Inbucket is an email testing application; it will accept messages for any email address and make...
sSMTP - sSMTP is a simple MTA to deliver mail from a computer to a mail server.
Sendmail - Sendmail is a general purpose internetwork email routing facility that supports many kinds of...
MailHog - MailHog is an email testing tool inspired by MailCatcher, but easier to install.
Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.