After a power outage (possibly complete coincidence but suspicious) Outlook 365 (desktop version) on 3 different Windows 10 machines (same Windows account), will load but not display HTML emails. Non HTML mails are ok. I only see the first line of HTML messages. This affects several different email accounts from different providers. When I look at webmail or my phone email the same mails look ok. Switching to a different network (eg use Wi-Fi over my 3G connection) makes no difference.

It seems to be related to my Windows account in some way but I am mystified as to what setting. It does not seem to be the basic Outlook security setting that stops loading HTML mails. Even with that off (so it should load HTML) only a small part of the email loads. In some cases the images load then immediately disappear, as if being hidden, leaving a white space. The same email account works ok on Outlook on another PC that does not share the same Windows logon.


This is a known issue. From Office 365:

Exchange Online service alert

Title: Issue affecting viewing email content in Outlook

ID: EX255650


Restoring Service


Issue affecting viewing email content in Outlook

User Impact:

Users may be unable to view email message content within Outlook. More info: Impact is specific to the Outlook client and users with access to other protocols, such as Outlook on the web or the Outlook mobile app, can view message content in those platforms as a potential workaround while our fix is applied.

Current status:

We’ve identified the underlying cause of impact and are applying a fix. This fix will reach all affected users incrementally over the course of the next four-to-five hours. Once users receive the fix, they will need to restart their email client to apply the fix. In some circumstances, users may need to restart their client a second time for the changes to take effect. We expect to complete this process and restore service for all affected users by May 12, 2021, at 3:00 AM UTC. We encourage affected users who are able to do so to leverage the workarounds described above in the "more info" section of this post while we complete the process of fixing this problem. Scope of impact: This issue could affect any user attempting to view an email message in the Outlook client.

Root cause:

A recent change to systems that facilitate text display management for content within the Outlook client caused impact.

Next update by:

Wednesday, May 12, 2021, at 3:00 AM UTC

FYI, Office 365 service alerts are emailed to all tenant admins. Make sure you have a tenant admin that can receive email so that you get these alerts.

You can also check Office 365 service health at the URL below:



Here is the detailed information about the failure, it is solved now:

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.