Hello
When you said this is your work email, can you clarify - is it a free outlook.com address you use for work purpose, or do you get this email from your employer?
Have you tried sending yourself an email from a different address, and see if it bounces? If so, what does the bounce say?
There can be some other things to check too, but I will wait for you to confirm if this is free outlook.com address, or address assigned by work, as the instructions are different.