I get a lot of email and I use a number of techniques to manage it. I also get some email from systems that are not things I process in email. For example, someone submits an expense report and I need to approve it. That sends me an email but the email is pointless since the work has to happen in the browser. For emails like this that are always actions, I've found it nice to route them straight into my OmniFocus Inbox using a rule. (The Omni Sync service allows you to have an email address that routes straight to your inbox.)
I use a rule like the one above to automatically shove these system emails into my Inbox and then close them out in my task workflow and outside of email. It’s a great way to keep email clean and automatically get these next actions in my system.