Hi @31530271 ,
Welcome to Microsoft Q&A!
From the description, seems that you are having issues with the App for Outlook integration in CRM 2016.
Please understand that the tags like Exchange Online and Outlook are mainly for general questions about Exchange Online or Outlook, while your question is more related to Dynamics CRM which is currently not yet supported in Q&A, so, I'd recommended trying to repost your question to the dedicated community for Dynamics as there might be more users who are familiar with how to integrate App for Outlook in CRM and hopefully you can get some insight over there.
https://community.dynamics.com/globalsearch/?q=app+for+outlook
Thanks for your understanding and hope your issue can get resolved soon.
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