No offense, but...

Why would you start an email with "As you are already aware"? If the person is already aware, then it's simply a waste of words. Otherwise, you're lying.

In this case, you're lying. "As you are aware, we're doing yadda, so obviously you need to yadda." Um... as I am what? Okay. Also, hey, if my design choice is gonna cause problems? I'm happy to change it. But try not to make it sound like I'm just a stupid doofus who's doing stuff wrong, okay? As you're aware, I'm pretty bright and you're a bunch of jerks.

Okay, not. But I needed to rant.