I am using Linux Mint 20.3 Cinnamon and Gnome Evolution Mail Client 3.36.5

Recently after some policy changes by Google Mail, my Evolution could not login to my gmail account and keep giving error message like

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You can’t sign in because GNOME Evolution sent an invalid request. You can try again later, or contact the developer about this issue. Learn more about this error

If you are a developer of GNOME Evolution, see error details.

Error 400: invalid_request

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It was very irritating and I wanted Evolution to work with GMAIL again. I searched EVOLUTION forums, Github etc but was not getting any solution. Someone suggested to upgrade Evolution to Ver 3.44 etc. but on Linux Mint official Repo it was not available and some reviews suggested even latest Ver also doesn't work with google authentication.

SURPRISINGLY and ACCIDENTALLY I found a working solution and now I am able to use Gmail with my EVOLUTION without upgrading.

In Linux Mint --> From Start Menu --> Go to "Online Accounts" --> Go to Add an account --> Select GOOGLE --> Provide your Gmail ID and Complete authentication process.

Once the authentication is done in "Gnome Online Accounts" ;

Go to Evolution Email --> YOU WILL FIND YOUR Gmail ACCOUNT IS ALREADY LISTED AND WORKING FLAWLESSLY without asking for any further authentication

:)