forged addresses

Hi, I'm not sure if there was ever a thread on this, but I was wondering if anyone can determine your real email address, if you were to fake it to your email client. I hope that this doesn't offend anyone, since this is a high traffic list, but I was wondering if this would work. To try it out, I setup my client to think I was someone else, and sent myself an email. I could only figure out what ISP it came from. What I would like to know is, can any of the experts on this list determine my address from the header of this post?? again, if this is something that I shouldn't have done, just let me know, and it won't happen again.