One of my favorite features of OmniFocus is the "Send to Inbox" shortcut. When a message is highlighted in Apple Mail I can press a keyboard shortcut (defined in system preferences) and a new Task is created where the task title = Subject of the e-mail and the description is a local link back to the selected message.
To be clear this doesn't load the contents of the e-mail into OmniFocus, just creates a URL that when clicked on my local machine opens the original message in Apple Mail. Hugely helpful for getting to inbox zero and then responding to the original message when the tasks complete!
More info on how it works in Omni: https://support.omnigroup.com/omnifocus-clip-o-tron/
Otherwise support for AppleScript would be much appreciated so folks could build simple workflows like this: https://gist.github.com/rentzsch/05d155147e894bd2730f