A customer upgraded to OS X Sierra on his MBP and his iMac
iCloud is configured with keychain sync
Mail accounts automatically get configured thanks to the keychain sync
Unfortunately on the iMac, Mail keeps asking for the password for one of the five email accounts; always the same
The request disappeared for a few hours and now is back
Is this a keychain corruption issue ? Yesterday, immediately following the Sierra upgrade I placed the ~/Library/keychain folder into the bin on both machines
Any ideas ?