Outlook Web Add-in: Categories are not being set

azureblue 0 Reputation points

Hello MS Office developers!

I have a question regarding the development of Outlook Addins.
I've tried to set the category of a mail, by using the JS API(https://learn.microsoft.com/en-us/office/dev/add-ins/outlook/categories) as well as by sending an EWS-Request.
Both approaches work on most mails, however, on some mails the category is not beeing set, even though I receive a success message from the API.

Did any of you struggle with the same issue? If yes how did you solve it?

Some background infos:
Test Environment Version: Outlook 365 16.0.14326.20702 32-Bit
Hybrid Exchange Version: 15.1 (Build 2176.2)


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