Email, everyday, and twice on Sunday. If you just give me an email address, I can put it in my contacts and contact you from the same place I contact everybody else: my email client. And I have a record of the outgoing message, and threading in the client to keep your response and my message associated, etc. I can also use CC, BCC, etc. with email, which I can't quickly and conveniently do with your form. But I don't want to be forced to copy & paste stuff.

So yeah, I come down strongly in favor of an email address.