Outlook 365 - Error after accept invites

Question

A few days ago some users reported, when they accepting /declining internal Outlook appointment invitations, then they recieve immediatelly an Email with Error:

"***This message could not be sent. You do not have the permission to send the message on behalf of the specified user.

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Diagnostic information for administrators:

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Error is [0x80070005-0x000004dc-0x00000524].***"

-> It can be solved by waiting one, two days and then it is working again without any interaction done by admins.
or when the OST File was deleted and a new Profile was created. Then it worked also fine again.

Only happing on Windows 11 devices

How can I understand this behavior?

Answer 1

Hi @Auburger, Benedikt ,

Welcome to our forum!

I noticed that the issue occurred a few days ago, have you done any specific operations before that?
And what's the version of your Outlook 365? (File > Office Account > About Outlook). Please make sure you have upgraded your Outlook to the latest version.

Based on my research on the error you provide, I found an article mentioned that the issue may be related to the Hybrid Configuration wizard, as shown in the below figure:

If it's your issue, please try the solution in this official article: "0x80070005-0x0004dc-0x000524" error when a user sends updates to Calendar items that were created before Exchange Online migration (microsoft.com).

Hope the above help!

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