Unfortunately spammers make money.
Anywhere you give out your email address you are at risk.
Even on this forum, don't make your email address public or viewable.
Robots are setup by spammers to specifically harvest email addresses, these lists are then sold to people who use them for spamming.
Its a big business and the spammers make a lot of money out of it, thats why spamming has become such a problem.
Some bussineses use mailing lists to inform their clients about products or new releases unfortunately the lists always fall into the wrong hands.
If you don't want spam, don't have an email address (which is pretty hard to do in this day and age) at least don't give it out, don't subscribe to information services (Just about everyone including banks sell your information for profit)
Peterp