That helped me. I had to set up a App-Password (see: https://support.google.com/accounts/answer/185833 ) for K9 as I enabled two factor authentication. This password is than used instead of the normal Google Password.
Solved it for me. -- You received this message because you are subscribed to the Google Groups "K-9 Mail" group. To unsubscribe from this group and stop receiving emails from it, send an email to k-9-mail+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/k-9-mail/b1be860b-9f0b-49fa-a7ca-4d6e4c79e7e6%40googlegroups.com.
