I checked out that thread you replied, and those are from 2010.
As I understand it Gmail used to allow “insecure logins” up until maybe a year ago.
I’ll re-try things, but I spent a good bit of time trying to get it to work for my Haiku video.
I have a second one planned, but haven’t had time to start on it and I’m currently running Haiku inside of VMware.
I’ve struggled with e-mail apps before as it’s my preferred way to use mail on Linux.
I guess Google still allows you to set an application specific password. I use old email software that requires an application specific password to work.
You can still use app passwords
https://myaccount.google.com/apppasswords