I'm a Thunderbird user almost since day one, but now I'm looking for something else. For whatever reason, it doesn't work well for me - every once in a while it becomes non-responsive (UI completely frozen for several seconds, CPU usage goes to 100%) and I just can't afford to waste time waiting for the email software to start working again.
My main desktop platform is Linux, but I need a client that works the same and looks the same on Windows too. Email server is IMAP with a pretty hefty account: over a hundred folders, hundreds of thousands of messages total (server-side filtering with Sieve). Typically it's a remote session, over VPN. So the client better work well, and be glitch-free.
The issues with Thunderbird might be related to the size of my IMAP account, plus the VPN latency - but frankly, I don't care, the client needs to hide all that stuff from me, do the updates or whatever in the background, instead of blocking the UI until it's done. Ironically, it blocked when I was done with this paragraph and I hit Enter. Sticking it to the man one last time, I guess.
Any suggestions? Thanks.