Can you please share the project , packages version and of course Studio version ?
As for your initial issues, you were using the old legacy activates and when doing so one must make sure that you set the correct type to the for each . To be more explicit the get outlook mail messages returns a list of messages , and the type of this list is System.Net.Mail.MailMessage
And you would have to be set the type of object that for each uses
Then the options should be available on the iterator
Now if you would choose to use the modern mail activities the whole thing becomes more simpler
but do please share the project , packages version and Studio version because I’m a bit puzzled by the message box not showing
Regards,
Dragos.