Spammers steal, swap, or buy lists of valid e-mail addresses
(and the addresses of people who have responded to spam command
a premium). Spammers also build their own lists using special
software that rapidly generates millions of random e-mail
addresses from well-known providers, such as MSN Hotmail and
others, and then sends messages to these addresses. Invalid
e-mail accounts return e-mail to the sender, so the software
very rapidly records which e-mail addresses are active and which
are not.
Some spammers also gather or harvest addresses from Web sites
where people sign up for free offers, enter contests, and so on.
Harvesters may also use programs (known as Web bots) that trawl
for e-mail addresses anywhere they're posted for all to see—on
Internet white pages, job postings, newsgroups, message boards,
chat rooms, and even personal Web pages.
(above wrıtıng www.microsoft.com from
receipt)
