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Office 365 Monitoring: Exchange Online Outage

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Jaap Wesselius
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Users Cannot access their mailbox via Outlook on the web in Exchange Online

On Monday April 20, 2020 starting at 9:30PM UTC, Microsoft experienced issues in Exchange Online, specifically Outlook on the Web.

When Accessing Outlook on the Web, the following error was shown:


Issues have been reported (on Twitter) from all over the US, Australia and Japan, but it looks like not all tenants have been impacted by this. Additionally, not all users were impacted as some users were able to logon using Outlook. At the time of this writing, I haven’t heard anything from Europe, but maybe it’s because it was mostly during the night.

The problem was caused by a service update for the Outlook on the Web user interface that contained code that caused this issue. This is strange, one might think that a software company like Microsoft has enough (code) testing facilities to prevent these kind of issues.

On Tuesday April 21, 2020 at 6:40 AM UTC Microsoft reported this issue as resolved, as their monitoring and telemetry did not show any issues anymore. Microsoft is continuing to investigate why this error slipped through their development and test cycles.

The Importance of Office 365 Monitoring

Yesterday’s (April 20th) outage, has been one of a string of outages that have hit Office 365 during the global health crisis.

  • April 14, 2020: Teams Outage (TM209306)
  • April 2, 2020: SharePoint Online Outage (SP208445)
  • March 17, 2020: Teams Chat Outage (TM206556)

Now more than ever, IT and end users alike are relying on cloud-based systems to fulfill their job duties and collaborate with one another. With end users now working outside of HQ, IT Pro’s now have even less visibility into their end users experience and are oftentimes reliant on end user complaints to verify the impact of an outage.

For example, yesterday the SHD advisory took a while to update while the first official notification was made on Twitter stating that "users may be unable to access Exchange mailbox via multiple protocols."

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Office 365 Monitoring with ENow

This is another instance that underscores the importance of Office 365 monitoring from an end user experience point of view in order to understand how organizations are impacted during vendor outages. This degree of vagueness leaves administrators wondering what is working and what is not working for employees within my organization? Is Outlook, Outlook mobile, or Outlook on the web having an issue or is it EWS? 

With ENow’s Office 365 Monitoring & Reporting Solution, IT Pros are able to go visually monitor their entire environment from a single pane of glass. When an outage occurs, the visual bread crumb trail enables IT Pros to pinpoint the root cause with confidence.


When an outage does occur, IT Pros can take the guess work out of the impact and are able to see which services and subset of services are affected with ENow’s remote probes. The end user experience monitoring probes can be installed where your end users are and cover a wide range of Office 365 app and other cloud-based collaboration systems (OneDrive, Teams, Zoom, Salesforce).

Lastly, the ENow dashboard provides visibility into the main places IT Pro’s typically go to learn more about outages, namely the Service-Health-Dashboard and Twitter. Thus, providing a single place to obtain information on service outages.

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The Importance of Office 365 Monitoring

In a cloud-world, outages are bound to happen. While Microsoft is responsible for restoring service during outages, IT needs to take ownership of their environment and user experience. It is crucial to have greater visibility into business impacts during a service outage the moment it happens.

ENow’s Office 365 Monitoring and Reporting solution enables IT Pros to pinpoint the exact services effected and root cause of the issues an organization is experiencing during a service outage by providing:

  • The ability to monitor entire environments in one place with ENow’s OneLook dashboard which makes identifying a problem fast and easy without having to scramble through Twitter and the Service Health Dashboard looking for answers.
  • A full picture of all services and subset of services affected during an outage with ENow’s remote probes which covers several Office 365 apps and other cloud-based collaboration services.

Identify the scope of Office 365 service outage impacts and restore workplace productivity with ENow’s Office 365 Monitoring and Reporting solution. Access your free 14-day trial today!

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