Can't get Gmail work with Apple Mail
I have a 13-inch mid-2012 MBP on High Sierra (HS) [version 10.13.6] and was using Apple Mail until a week ago after I changed my Google password. I then launched Apple Mail, entered the new password, and a 400 error was shown. Ever since I could not use Apple Mail. I tried recommendations in this and other networks to fix it with no success. I opened Gmail, checked under the 2-step verification, and could not find the app passwords. Since my knowledge of computer issues is limited I sought the help of a local guru who could not not solve the problem either.
In trying to see what happened “Apple Mail Connection Dr” was used with the following result, Please see sanpshot, Details and logos.
DETAILS
On a recently purchased Mac mini M2, the guru launched Apple Mail. He then entered the new Gmail password. There was no error 400 and I was able to use Apple Mail as usual. The guru said that something in the domain of Apple or Google environment is occurring that is not allowing me to get Apple Mail to work on HS, which is the computer that I use to work.
Moreover, Apple Mail in my old Mac mini on El Capitan also ceased to work some while ago. Is this now the destiny of Apple Mail on HS?
In case this info is needed, I can open Apple Mail from Safari, or Chrome, with no interference.
Desperate because we need to use Apple Mail in HS, are considering an alternative mail system. Hope this will not be the case. Please help
MacBook Pro 13″, macOS 10.13