Thunderbird - Built in Spamassasin

Using Thunderbird, in conjunction with your IMAP configured dovecot is by far the best method of synchronizing you mail folder with multiple devices. In Thunderbird you should instantly turn on your junk mail “adaptive filters”. You can also set custom filter rules to send messages with particular words in the header to the junk folder. Frankly I prefer using the graphical configuration of Thunderbird to the direct command line configuration of spamassasin. Thunderbird is powerful, and successfully filters out well over 95% of the spam I receive. I get closer and closer every day to completely avoiding all spam. Every day I set a new filter rule, and mark new messages as spam.