In part 4 of his series, Scott Davert continues showing off how to use various apps with an iOS Device and Bluetooth keyboard. This time around, Scott takes a look at the mail app. Part 1 which covers basics, can be found here, part 2 covering text editing can be heard by following this link, and part 3 covering Safari can be listened to here.
Unless I missed it, this podcast didn't cover deleting (or archiving) a message. It doesn't show up on the keyboard shortcuts. I can navigate to the archive button when using the iPhone, but this icon is particularly difficult to get to on the iPad (control plus up or down arrows don't take you anywhere near it).
In the list of messages, swipe up/down to get to the delete option. But, apparently there is no keyboard shortcut to do this while in the middle of reading the message. You must escape back to the list of messages to do this.