I think maybe sometimes that happens when the mail server is too slow to respond?
It happened on my OP 3 just yesterday - it’s my backup of the backup device and I only turn it on like once/month to update apps and stuff, so I thought maybe I hadn’t changed to OAuth yet. But everything was set up properly and a few minutes later it worked again.
I don’t think it’s really k-9’s fault … more like a glitch where the mail provider, server or even just the device or internet connection glitch out for a minute. I tend to ignore it and just check a few minutes later.
I tend to ignore it and just check a few minutes later.
That's what I have been doing and probably will continue doing, though perhaps I'll post something on Google's Gmail forum and see what kind of help there might be. If I get anything useful I'll post it here. Thanks.