Popular SMTP servers for temp mail

We found on the Internet the top of the popular sites (alexa more then 200k) that provide temporary mail services and, for curiosity, looked at what they were doing inside their SMTP servers.

So which servers are most popular?

Postfix - It is Wietse Venema's mail server that started life at IBM research as an alternative to the widely-used Sendmail program. Now at Google, Wietse continues to support Postfix.
site: http://www.postfix.org/
  • 10minutemail.com
  • mailinator.com
  • fakemailgenerator.com
  • guerrillamail.com
  • mytemp.email
  • crazymailing.com
  • throwawaymail.com
  • tempr.email
  • minuteinbox.com
  • emailtemporal.org (mandrillapp)
  • byom.de
  • moakt.com
  • mohmal.com

Haraka - open source SMTP server written in Node.js
site: http://haraka.github.io/
  • temp-mail.org
  • getnada.com
  • getairmail.com

Exim - is a mail transfer agent (MTA) used in Unixllike operating systems. The first version was written in 1995 by Philip Hazel for use in the University of Cambridge Computing Service's e-mail systems. Exim is distributed under the GPL, and therefore is free to download, use and modify.
site: http://www.exim.org/
  • 10minutemail.net
  • tempmail.net

generic Erlang SMTP server - framework that can be extended via callback modules in the OTP style. A pure Erlang SMTP client is also included. The goal is to make it easy to send and receive email in Erlang without the hassle of POP/IMAP.
site: https://github.com/Vagabond/gen_smtp
  • dropmail.me

maildrop - written in Scala, with heavy use of Akka actors and the Play Framework.
site: https://github.com/m242/maildrop
  • maildrop.cc