The first level for setting up spam filtering is to do it at the server level or on your personal computer.

It is also amazingly accurate and only very rarely grabs a legitimate message and identifies it as spam. I used all of them in conjunction and found that Thunderbird effectively filtered out almost every undesirable message. There are actually several methods for filtering out spam using Thunderbird’s tools. This tutorial shows you how to turn these filters on and configure them to meet your needs.

As part of my battle to eliminate spam, I found that Thunderbird contains some amazingly powerful spam and junk mail controls that are very effective at filtering unwanted email. It turns out that a client thought she was doing me a favor when she posted it on a forum, along with a recommendation. I have always protected my e-mail addresses, but recently ended up receiving more than 100 spam messages per day on my most important e-mail address used only by my business clients. No one want to receive spam, but today it is almost inevitable that most e-mail addresses will eventually end up on spam lists.

Mozilla thunderbird mail filter