A few steps to help us to trouble shoot the problem with your email account.
1. Are you not able to send and receive mail?
2. Have you checked that you have a working internet connection
3. Test by making use of a different internet connection or hotspot.
4. Have you changed your internet connecton or internet service provider
5. Have you changed or upgraded devices eg computer, laptop, tablet or cell phone
– Check your email set up settings
6. Is your Microsoft Software subscription up to date, outstanding subscription can cause problems with outlook
7. What type of errors are you receiving?
8. Have you tried sending a test email to yourself
9. Which mailboxes is it for?
10. Are the users experiencing it on all their devices?
11. Are they users using the same network?
If so, what is the IP address?
The following site will give you your current IP address: https://www.whatismyip.com