getOauth64()
getOauth64() : string
Generate a base64-encoded OAuth token ensuring that the access token has not expired.
The string to be base 64 encoded should be in the form: "user=<user_email_address>\001auth=Bearer <access_token>\001\001"
OAuthTokenProvider - OAuth2 token provider interface.
Provides base64 encoded OAuth2 auth strings for SMTP authentication.