OK Bat lovers, what am I missing if Thunderbird works for me? I'm OK w/ the bird, but it has a few nits.
Thunderbird is a -good- mail client, especially for the price. Think of it as a screwdriver you got free for a store promotional or something. The Bat! is a power drill. It does everything Thunderbird (or anything else) can do +++.
Does the Bat have junk mail filters? Can it check all my 5 email accounts with one click?
TB doesn't have a built in junk mail filter, it has support for plugins. That said, there are a few alternative plugins available as well. I'm presently testing out a 12$ shareware spam filter, antispamservant, to see how it stacks up. Thus far, I'm very impressed with its bayesian implementation.
As for checking all your accounts with one click, yes. F2, by default -- though all keyboard shortcuts are configurable.
Some highlight features -- scheduler. You can have TB automatically back itself up, send messages at a certain date (It sends birthday wishes to my family, so I can forget with a clear conscience). Templates -- TB has the most powerful template system available. The advanced template editing has a bit of a learning curve, though.
Eh, I can't list all the features. The real great thing is, if you can imagine it there's a good chance TB can do it -- whether it's specifying different signatures/from address/templates/bcc's etc. on a per user, per list or per folder basis or just inserting a random quote in your sig, TB does it.
As for dealing with your multiple accounts, it has great virtual folder support -- so you could filter messages from all your accounts into virtual folders sorting mail by topic rather than account -- if you had a use for such a thing.
The drawback is documentation . . . rather, lack thereof. The documentation is terrible.