I use IMAP for a few accounts and from time to time it just doesn't work. Messages don't show up and I have to close mail and reopen etc etc. Can't delete multiple messages without an error. Now, Mail says its downloading messages but just hangs. Probably the next step will be to delete accounts and re add which is a joke. This issue is on a few thousand dollar iMac with a mail program thats junk. However, my few hundred dollar iPhone works like a champ. Always works. Whats wrong with this picture. I'd hate to jump on that bus but I have to say it. Nothing seems to work like it use to Apple. I use to rely on this 100% of the time and never have any issues. Not anymore. Especially on my iMac and Mail. Looks like its time to bag Mail once again and go back to Airmail. What a joke Apple.