How can prevent certain senders from going to Junk Mail without creating contact?

I am running Mountain Lion 10.8 and use Mail.app for my email mostly.* I recently purchased a product from Amazon, somewhere I order from frequently, and noticed that I didn't receive the usual sales receipt - or so I thought. I looked in Gmail's All Mail folder and noticed it there. Mail.app had deemed it Junk and put it in the Junk folder (which I don't believe is accessible from iOS devices with typical IMAP email set up on them).

This is what my Junk Mail preferences look like when this happened:

Is there a way to tell Mail.app that a certain sender (preferably something such as "all senders from @example.com are not junk" vs. the actual [email protected]) is not Junk without actually putting the sender into my contacts?

* I now use AirMail because Apple Mail was using a lot of disk space (among other reasons).

Yes — by selecting "Perform custom actions" and then clicking "Advanced," you can configure Mail's internal rule that determines both what is considered junk mail and what Mail should do with it. Add a condition to this rule that reads "From does not contain @example.com", and no such mail will be considered junk.

As far as I know, this is the only mail rule that can determine whether something is marked as junk or not. Ordinary rules can only move messages into or out of the Junk folder.