This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The From address is used to send replies to; if it doesn't exist, of course the mail bounces.
Furthermore, the xyz.com domain exists; the people who run it might not like you messing around with it (not to mention that they might have set up a catch-all email account that would happily accept whatever you send there WITHOUT bouncing it). [ May 15, 2008: Message edited by: Ulf Dittmer ]