Це стара версія документу!
http://www.postfix.org/features.html
http://wiki2.dovecot.org/
http://wiki2.dovecot.org/QuickConfiguration
http://www.brennan.id.au/12-Sendmail_Server.html
http://www.squirrelmail.org/about/
http://www.courier-mta.org/sqwebmail/
http://www.openspf.org/
http://www.openspf.org/FAQ/Common_mistakes
http://serverfault.com/questions/369460/what-are-spf-records-and-how-do-i-configure-them
http://xmodulo.com/mail-server-ubuntu-debian.html
https://www.linode.com/docs/email/running-a-mail-server
https://wiki.debian.org/Postfix