A common pattern in the way Worms and one tactic Spammers employ
is that they send mails which have spoofed from address. This
means that the from address you see in the mail is not actually
the address from which the mail originated. Worm when it infects
a PC, makes a list of all e-mail addresses found in the infected
machines address book, html pages, or any other file is searched
and a list is made by the worm. Then it chooses one 'from'
address and another address as the 'to'. The person whom it
supposedly come from, may not know about the mail at follow
similar procedure so that the source of the spam is hidden,
bounced back message goes to spoofed addressee, and spoofing
also allows spammers to avoid negative publicity. Bounced Mail;
when the mail is sent to someone fraudulently with your from
address and if for some reason that mail could not go through,
it gets bounced back to you. This is how you get undeliverable
message for mails which you haven't sent. Mail may be getting
returned due to over quot