Best practice with Mail integration?

I can’t remember, sorry. I ultimately gave up on Mail and switched to Spark.

Thank you for letting me know.

Hi there!
New Mail has a (very odd!) way to send emails to OF. My OF3 installed a service for that, so if you go to Mail’s “Mail” menu, then “Services” the OF service “OF3:send to inbox” appears and that’s it! You may also give a shortcut to that OF service and when you are in the Mail list, with a message selected, go ahead and press that shortcut and it goes to a OF inbox window.
Of course this is a very odd way of doing things, the services should be available when you select an email and right click the mouse…