Mail.app keeps asking for account password?

[MightyMagpie]

Set To Manual

Personally, I'd like so see Apple become a little more descriptive with these messages, since obviously it's not an issue of supplying the wrong password. Incidentally I was just monitoring this problem right when you posted. I opened terminal and left a ping going of my mail server in the background. It usually averages around 75 ms round trip; when Mail hiccups, the round trip time is running longer than that. Not sure if it's a coincidence.

Out of curiosity, for those experiencing this problem, how frequently do you have Mail configured to check the server for new mail? Mine is set to every minute, so I'm going to back off the frequency and see if that helps...

I have had this issue for more than 6 months. I have called Apple, checked keychains, rebuilt mailboxes etc all to no avail. I decided to change my check for mail preferences from every minute to Manual. I have not had a reoccurrence of this issue since. Fingers crossed!
Thanks to all previous contributors on this site who have alerted me to the resolution.