I've used Claws off & on for a while.
If HTML is VERY important, I'd suggest you check if it does what you want before you commit. I find that some images don't render. That can be an advantage, but you might like better.
Also, it seems to slow down with total file numbers somewhat less than you are contemplating. (But I prefer POP, so maybe that has a bearing.)
On Tue, Jul 2, 2013 at 3:11 PM, Jason White
<jason@jasonjgw.net> wrote:
I've read good reports about Claws-mail. Perhaps a subscriber to this list has
used it and can comment further.
--
Keith Bainbridge
0447 667 468