There is a widespread issue with Microsoft office 365. If your email is with Microsoft you may be having issues connecting to mail. Some users are reporting that their phones are working for email.

You may ahve some users in your organization that are working and some that are not.

Microsoft is aware of the issue and is working on resolving. I understand that they are making some DNS changes to resolve the issue. You may want to try restarting your PC ever hour or so to force the DNS settings to get the updates information.

I will update here when I hear any changes.