IMAP emails disappearing from Apple mail on one computer when moved on another!
I'm sorry but you're getting it wrong. This is the expected behavior of IMAP. IMAP is to keep all devices synced with the server. That means, if you delete an email on one computer, it eventually disappears from all the others. If you mark something as read on one computer, it eventually gets marked as read on all of the others. I hope this clears things up.