Guerrilla Mail - Guerrilla Mail is a web-based app that provides a disposable and anonymous email address. Users of the service are not required to set up an account in order to send or receive emails.
MailDrop - maildrop is a Mail delivery agent used by the Courier Mail Server. The maildrop MDA also includes filtering functionality. maildrop receives mail via stdin and delivers in both Maildir and mbox formats.
Firefox Relay - Keep your email safe from hackers & trackers...
10 Minute Mail - Temporary disposable e-mail service to beat spam. Avoid spam with a free secure e-mail address.
Mailinator - Any Inbox. Any Time.
YOPmail - YOPmail is an interesting anonymous mail program that allows users to communicate with each other without compromising their original email addresses. Read more about YOPmail.