POP-Before-SMTP-Auth is a POP before SMTP daemon for Dovecot and Postfix that works by scanning mail server log files. The line-matching regex can be changed from the configuration file, in case Dovecot's logging format changes, and also to adapt the script for use with something besides Dovecot. Presently the script requires that the IP address appear on a single line with the successful login in the log file.
DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any email/calendar client (e.g. Thunderbird with Lightning or Apple iCal) with an Exchange server, even from the Internet or behind a firewall through Outlook Web Access. DavMail now includes an LDAP gateway to Exchange global address book and user personal contacts to allow recipient address completion in the mail compose window, and full calendar support with attendees free/busy display.
Inbucket is an email testing service, similar to Mailinator. It accepts messages for any email address and makes them available to view via a Web interface. It allows Web developers, software engineers, and system administrators to quickly see the emailed output of their applications. No per-account setup is required. Mailboxes are created on the fly as mail is received for them, and no password is required to browse the content of the mailboxes.