In rare cases, while using the "Launch Outlook" action, the application may ask the user to select a profile.

In those cases, we need to make sure that the machine's "Mail" settings have been configured correctly:

Should the issue persists, use the following workaround: 

Open Outlook with the "Run application" action (instead of "Launch Outlook") and then go on with the "Launch Outlook" action to attach to the running instance of the application.