If it is about fixing a temporary Gmail error then, in that case, it is advisable to get all the cache and cookies cleared from the browser after that also the user should also get the firewall and the antivirus software disabled also the user should get the Gmail server settings configured, if needed then for further information the user should get connected with the certified Gmail technicians.

http://www.email-helpline-number.co.uk/gmail-customer-services.php