Custom Workflows - Chain Actions
Just like it sounds - create custom actions/workflows through chaining of built-in actions.
Example workflows (that I currently chain manually):
1. In the message list: Send to OmniFocus, then Archive.
2. In the Compose windows: Send Email, then find sent email, and send copied email to OmniFocus
The second implies custom Send actions in the Compose window...

-
R H van der Gaag commented
I'd really like having a custom action that I already have and use in the iOS version: forward a message to my p.a. (without any further editing needed from me).
-
Michael Carney commented
Yes! I was getting ready to ask for exactly this when I found your suggestion. I'd also add the ability to "Send to OmniFocus and Delete" and related actions.