I have used High Impact Email Platinum for a client before. Some assets (graphics, images) were made in XDP.

There are many problems with doing it yourself. For one, you have to allow for people to unsubscribe by the laws in most countries and maintaining that list is onerous. Second, most ISPs have restrictions for bulk email and you will likely get marked as a spammer even if you can get the emails to send.

It is just not a good idea to do it yourself for these and other reasons.

http://www.templatezone.com

Mike