I am running 12.6 - Build #12.6.0.738 and at least once a day I get an error for 1 out of the 3 Incoming Mail Accounts that are all set exactly the same with imap gmail with SSL Port 993 saying Authentication Failed. But the password is entered correctly and it will work most of the day but at random times fail. I have the allow less secure apps setting in Gmail turned on already and the other two gmail accounts never throw this error and have the same settings just a different email address. Here are screenshots of the setup and the error I get. Any help would be appreciated.