You can try to reconstruct the damaged MAPI32.dll file to fix the QuickBooks Outlook is not responding error.
Terminate all the QuickBooks background processes running on the system.
Then, go to the Windows Explorer using the Windows+E keys and then go to the C:\ Windows \ System32 Directory path.
After that, search for the Fixmapi.exe file in the same System32 directory.
You can also try to search it through the Windows Search Program.
In the end, when the Repair Process gets completed, re-try to send an Email.
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