Office 365 – problem

Office 365 – problem

On Tuesday we identified a “funny” little thing when using the web version of outlook.

If we invited an internal user to a meeting and that user only had two letters in his alias the invite failed (, invitations to internal people with mail addresses that had more that two letters worked without problems.

When we did the invite we saw the following error (One or more attendees have invalid email addresses).


As soon as you entered the name it turned red, meaning invalid address.


The same problem was seen when you tried to reply to an internal mail from a user with only two letters in the mail address.

I was able to reproduce the same problem on more different tenants, so no other way than contacting Office 365 support (around 17:00 Danish time).

Together with support I tested the old version of the web interface and it was working as expected.

We then did a fiddler trace and saved HTML code on the pages and the Escalation Engineer had to do his job, I must admit that I thought that it would probably take some time before they returned Smile

So it was a very positive surprise that the problem was fixed just around noon on Wednesday (Danish time), unfortunately Microsoft has not reported anything back on the case, which is a little bit strange, I was so ready to give them credit for the quick fix, but let’s see what kind of answer the return.

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Modern Workplace consultant and a Microsoft MVP in Enterprise Mobility.
Modern Workplace consultant and a Microsoft MVP in Windows and Devices for IT.

Infrastructure architect with focus on Modern Workplace and Microsoft 365 security.

Cloud & security specialist with focus on Microsoft backend products and cloud technologies.

Cloud & security specialist with focus on Microsoft 365.

Cloud & Security Specialist, with a passion for all things Cybersecurity

Cloud and infrastructure security specialist with background in networking.

Infrastructure architect with focus on design, implementation, migration and consolidation.

Infrastructure consultant with focus on cloud solutions in Office365 and Azure.

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