Using an earlier version of Outlook, we used to be able to click in the Adagio field “Email” (in AR Customers, for example) when there is an email address entered in the field.
This would automatically open an Outlook "New Email" screen, ready for sending out, with the “To” address filled in with the address that displays in the Adagio field.

Now, we upgraded to Outlook 365. And now when we click on the email field in Adagio, it does not take us to a New Email page in Outlook. Instead, it prompts for the “application to open the mailto link”.

How do we make this work directly with Outlook 365?

Check your default applications in Windows and change the Email default application to Outlook 365.

Also, depending on the version of Office 365 you got, you may not have local installs of the applications. That could also play a factor. Does Excel Direct work?

Thanks Dan for your suggestions.
I may not be back at this client for a day or two. I will check all this out when I can and let you know.