Big Sur OS upgrade
Having upgraded my AirMac (early 2014 vintage) I now can't send emails on my Googlemail account but I can receive them - 'lightning bolt' symbol next to All Inboxes label. When clicked on ask me to go to Browser and login with my Google password, I go thru the whole two step authentication routine but I still can't login. Tried changing my password but no change still the same problem. I've a similar problem with an Hotmail account receive but not send. Tried - & + them in Internet Accounts - problem remains. Internet Accounts shows both a googlemail and a gmail account both for me. I've never set up a gmail account - do googlemail accounts default to gmail now. Fortunately I've other devices and I can use my googlemail thru Chrome.
Any help would be appreciated.
MacBook Air 11″, macOS 11.7