If I ever release a program that has an exclamation point at the end of its name, please shoot me.
Really. I find it pretty stupid as well. I always hated the name Yahoo! chose as well. See, didn't you mentally think "end of sentence" after "Yahoo!"?
Regarding PocoMail... What exactly is confusing about handling multiple accounts? You can easily specify the incoming and outgoing mailboxes to use (and you can specify any one of your mailboxes for each), and you can use filters for more control.
Still, I will give TheBat! a look (you did it again after the "!", didn't you?). I'm tired of PocoMail's bugs. None are severe, but putting up with several minor-but-annoying bugs has put my blood on a slow boil, especially when the author was notified of these bugs years ago in some cases.