"I've been using Claws Mail on Ubuntu for years now. Before that I used KMail, Thunderbird, and various others. I'm very happy with Claws and I much prefer it to Thunderbird because it's so much simpler and much, much, faster. I am using it strictly for POP/SMTD mail but it does IMAP as well (although I haven't tried that feature)."
So can I import from Thunderbird, multiple email accounts with the minimum of hassle?