It looks like the app isn't installed for your Outlook mailbox error occurs when using Dynamics 365 App for Outlook
This article provides a resolution for the issue that you can't open the Microsoft Dynamics 365 App for Outlook on a Mac due to the It looks like the app isn't installed for your Outlook mailbox error.
Applies to: Microsoft Dynamics 365
Original KB number: 4295094
When you open the Microsoft Dynamics 365 App for Outlook on a Mac, you encounter the following error message:
We're sorry. It looks like the app isn't installed for your Outlook mailbox. Please contact your system administrator.
This error can be caused by stale data in the Outlook for Mac web browser cache.
Fully clear the cache using the following steps:
- Start the Finder application.
- Hold the Option button down and then select the Go menu. The Library option should appear as one of the available options.
- Select the Library menu option. The Library folder view will appear.
- Under the Library folder, locate the Containers folder and expand it.
- Under the Containers folder, locate the com.MicrosoftOsfWebHost folder and expand it.
- To clear the web browser cache, you must move the following to the Trash:
- com.Microsoft.OsfWebHost/Data/Library/Caches/com.Microsoft.OsfWebHost (whole folder)
- com.Microsoft.OsfWebHost/Data Library/Cookies/Cookies.binarycookies (file)
- Restart Outlook and restart the Microsoft Dynamics 365 App for Outlook.