gmail stopped working in mac mail

Not recommending you change the PW at all...

Open Keychain Access in Utilities, then either check the Password under that item, change it to the new one, or delete it and start over when Mail asks for a PW.

There''ll be at least 2 entries, maybe more.

The trouble is that Mac Mail almost always chooses the old Passwords if you don't change or get rid of the old ones.

Well, let's try the PW thing anyway...

Open Keychain Access in Utilities, then either check the Password under that item, change it, or delete it and start over.

Enter the part after the @sign in the search bar.

You may have duplicate or more entries in Keychain Access.

If using a browser to login via WebMail works it's not Name or Password, but likely old passwords interfering.

Have you changed your password recently?

In the meantime use a Browser for WebMail...

https://gmail.com

Great news Jenelle, thanks for the report & good luck! :)