A fast, highly extensible, and event driven SMTPserver
...Haraka makes no attempt to be a mail store (like Exchange or Postfix/Exim/Qmail), a LDA, nor an IMAP server (like Dovecot or Courier). Haraka is typically used with such systems. Haraka has a scalable outbound mail delivery engine built in. Mail marked as relaying (such as via an auth plugin) is automatically queued for outbound delivery. Haraka's plugin architecture provides an easily extensible MTA that complements traditional MTAs that excel at managing mail stores but do not have sufficient filtering.
Local, web-based mailserver application. Slurp mails into oblivion!
MailSlurper is a small SMTPmailserver that slurps mail into oblivion! MailSlurper is perfect for individual developers or small teams writing mail-enabled applications that wish to test email functionality without the risk or hassle of installing and configuring a full-blown email server. It's simple to use! Simply set up MailSlurper, configure your code and/or application server to send mail through the address where MailSlurper is running, and start sending emails! ...