Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi, CerysMW
Thanks for posting into our community.
According to your description that your Gmail does not connect to the Exchange sever.
It is a fact that we received a lot feedback for the same issue that those customers solved it by using the two step verification on the Gmail server.
For more detailed information, please be kindly to ask the Gmail's support for the further assistance.
Thanks for your time and your understanding would be highly appreciated.
Sincerely,
Zed | Microsoft Community Moderator.