I know I'm a couple weeks late posting this, but the fine folks at Mozilla finally released Thunderbird 2.0. Now, I've wasted a lot of your time here in the past waffling between mail clients... but I've been using thunderbird consistently since the 2.0 betas and I think it might finally stick. Here's why (for me):
Also, while not a core feature, I'm very pleased with the new Growl add-on for new message notification (I had been using YAMB before which wasn't optimal.
Still on my wishlist: sender pictures (preferably from LDAP userpicture or mac address book integration) and better offline detection for OS X. Otherwise, I love it.
I finally experimented with a neat feature in one of my favourite apps for mac os x, growl. There is a very promising looking "Networking" tab in the preference pane for growl. I've often thought that this could be a cool feature, but it was non-obvious how to make it work. Essentially, I have found that it's easiest to play my music off of my mac mini - it has my 100gb collection mounted locally and is directly connected to my speakers - but I'd still like the song-change notification from growl when working on my powerbook (silly, perhaps, but I like it). So, with a little help on IRC from The_Tick, here's how:
That's it. It is that easy. The part that had me stuck was I was expecting the "Add computer" button to do something on my mini. Not true. It's all automatically discovered via bonjour. I was warned that it can be buggy and you can create infinite loops if you try to do two-way notification, but otherwise it's pretty cool if you ask me.