Occasionally when your email or other Office 365 service starts behaving abnormally, it is a good idea to check Office 365 service health as a first step to troubleshooting. It’s good to know if Microsoft’s systems are having an issue before you start worrying about your own. Checking Office 365 service health is a very simple process, with only one major flaw that I’ve found.
To begin, sign into Office 365 portal as an administrator for your organization. Once you are signed in, look down the left side of your screen
Next click on “service health” (highlighted in red in the picture above). This will take you to the service health screen that looks like this:
On this page you can view each aspect of Office 365 Service Health and when it has been up or down for the past week. Earlier I mentioned a major flaw I have observed that you may have guessed yourself already. If the administrator portal is down, you can’t view service health, which kind of negates the entire point of it in the first place. I suppose you can at least come back to it later when it is up and confirm that it is down, but when it comes to immediate diagnosis, this is rather annoying. I would much prefer they had an “external” service health page that existed outside of the administrator portal.