From: https://haraka.github.io/

Haraka is an open source SMTP server written in Node.js which provides extremely high 
performance coupled with a flexible plugin system allowing Javascript programmers full 
access to change the behaviour of the server. It is used heavily in some high traffic 
sites - see the "Known Users" link above for testimonials

From: http://serversmtp.com/en

turboSMTP is here to help, offering you 6.000 free emails per month (200/day) 
without restrictions and forever. This package is ideal for the ones who want 
to get both a free solution and all the qualities of a dedicated SMTP server. 
No credit cards are required. Try it now!

From: http://mailinator.com/index.jsp

temp email temporary disposable throw away

Free disposable email. Think up and give out a Mailinator address any time you need an email 
address but don't want to get spammed! 

From: http://www.lettermelater.com/forum.php?id=1

LetterMeLater.com allows you to send emails at any future date and time you choose.