Mail app El Capitan - Gmail "Login Failed" error
Hi, Since upgrading to El Capitan I am getting "Login Failed" error for my 2 Gmail accounts. I tried deleting the accounts and setting them up from new, still the errors. My other email accounts (non-Gmail) are connecting fine.
The Mail Connection Doctor says "Trying to login to this IMAP account failed. Verify that the username and password are correct." There is an equivalent error for it's SMTP account.
In Mail Settings, the Incoming Mail Server and User Name are greyed out (albeit containing the correct information), which I hadn't noticed with Yosemite Mail. The tick box to automatically detect and maintain account settings is ticked, and that option is greyed out; I cannot change it.
On rare occasions, the connection has been successful, and the emails download. This is sometimes after Mail has been sitting there open for a while. Then next time I start Mail, the errors are there again.
MacBook Pro (15-inch Mid 2012), OS X El Capitan (10.11.3), SSD, Optical Drive swapped for HD