Thunderbirds are go !
My old company used Exchange Server. I used to use Outlook for mail.
My new company uses IMAP. So now I can use Thunderbird for mail (news and RSS).
No more wasted time puzzling over why filter rules suddenly stop working.
No more wasted time messing around with proprietary PST files.
Fast, flexible, powerful search capability.
All my Outlook data imported seamlessly.
Small change, massive improvement.