Since upgrading to Ubuntu 13.10 my mail programs continuously ask for authentication (password). I use GMail and use the 2-step verification. I have entered the Google generated app password. Problem is, every time I input it works until I close the mail program and re-open, then it wants me to input the authentication again. So, I have to go to Google security, revoke access to the app and re-generate another one. What a hassle. At first, I thought maybe it was Thunderbird, so I tried Geary, then Sylpheed, then Claws. Same thing with all of them.
Any fixes? Is this a known issue with the upgrade?