As of February 15, 2021, sending emails with Google G Suite accounts will only be possible with apps that use OAuth.

OAuth2 Authentication is already implemented via the XOAuth2Authenticator. But it uses the password as acces_token. Since its validity is limited to one hour, this is not a practicable way.

At the moment i have written my own custom transport (gmail+oauth), since i have already included google/apiclient and oauth handling/storing in my app.

I think it makes sense to implement oauth token - handling / - renewing / - storage in symfony/google-mailer, otherwise it will make it obsolete after February 15, 2021.

What do you think. Maybe i could help out with this.