Mac Mail keeps losing the 2 factor auth passwords for Gmail My laptop (MacBook Pro late 2012 running OS X 10.10.5) has had an issue the last two mornings. When I turn it on I get a load of notifications saying that I need to re-enter the password for my internet accounts.

Digging a little deeper what has happened is the 2 factor auth passwords used for Mac Mail Gmail accounts have all been lost. Any ideas why this keeps happening overnight and what I can do to prevent it?

I've tried going to System Preferences > Internet Accounts and updating the passwords used to a Google app specific password (the system Google uses to get around applications that don't support their 2 factor auth) but when I do this it insists that I use a 2 factor login.
I had the same problem. I updated to Sierra and then Mail kept asking for password but did not help when I re-entered them. I dug deeper and found the ports needed to be corrected (in Mail Preferences). Did that and it works now.