public static void AuthenticateSmtpGoogleOAuth2(this SmtpClient imap, MailBox account, ILogger log = null)
{
if (log == null)
{
log = new NullLogger();
}
var auth = new GoogleOAuth2Authorization(log);
var grantedAccess = auth.RequestAccessToken(account.RefreshToken);
if (grantedAccess == null)
{
throw new ProtocolException("Access denied");
}
log.Info("Smtp SSL connecting to {0}", account.EMail);
imap.ConnectSsl(account.SmtpServer, account.SmtpPort);
log.Info("Smtp connecting OK {0}", account.EMail);
imap.SendEhloHelo();
log.Info("Smtp logging to {0} via OAuth 2.0", account.EMail);
imap.Authenticate(account.SmtpAccount, grantedAccess.AccessToken, SaslMechanism.OAuth2);
log.Info("Smtp logged to {0} via OAuth 2.0", account.EMail);
}