It's not mail art yet but all it needs is an address and a cancelled stamp, so I posted it just for the inspiration. Although I would leave the three-dimensional flowers off, as they pose a risk to getting the envelope caught in the machinery.
Handmade, drawing envelopes, great for cute snailmail. Create your own set (3, 5, 10 or 15 envelopes) http://www.etsy.com/shop/snailmailshop
Simple yet adorable. I just need to get a raindrop punch because I can't imagine cutting out all those raindrops!
I like this. someone's going to get a letter soon. Hand-decorated mail art envelope by Born 2 b Creative