Having been frustrated by Apple Mail I decided to try TBird. I especially liked that I can save attachments wherever I want, I am absolutely infuriated with Mail's insistence on storing messages in one opaque lump.

So on that TBird if quite nice. The prefs are sensible and mature, again much more adult-like than Mail's. E.g. you don't have to go thru prefs to get to filters. Which are called filters and not "rules". But I was suprised to see that TBird managed to underdo Mail on the filters themselves. Very few choices, all seem to be displayed whether you're gonna use them or not. The filters work only from the filter window, not from the menu. The conditions window does not prefill from the currently selected email (unlike Mail) which could be manageable except that the window DOES NOT ACCEPT PASTE! You must manually type in stuff. Moreover the windo is not movable when you are working on your filters so if it happens to cover the text you have to close the rule-setting slide-out first then move the filters window then reopen the rule-setting slide-out so you can see teh text you are trying to type in. I can't recommend TBird as long as the filtering is so bad. I'll check back on it with version 1.1.