| Mailer-Daemon | postfix |
| Email-Scanning | amavisd-new |
| Spamfilter | spamassassin |
| Mailserver (POP and IMAP) | cyrus-imapd |
| Viruscanner | SAVAPI SDK |
| Email Retrieval | fetchmail |
| Mailinglists | mlmmj |
| SMTP-Blocking (DNSBL) | postfwd2 |
| Webmail | Horde and IMP |
| Web-Groupware | Horde, Turba, Nag, Mnemo and Kronolith with storage backend for Kolab-XML |