I am not aware of any ISP that allows spam to continually run into a users mailbox without some sort of intervention. Most ISP's that I am aware of would eventually delete the account that is racking up the SPAM email because it causes a burden on the ISP itself. Remember that each email message that you receive takes up space
on a mailserver - eventually if you do not check and delete these messages, the ISP could delete them, and most spam detecting software deletes junk mail after say, 30 days or maybe a little more.
Eventually, the account could be deleted and if that is true, the mail would BOUNCE back to the sender. Everyone that has had an email address has gotten spam at one time in their internet journey, and most email accounts, even if you just make a new one and let it sit there for a month
you would get some spam mail if you don't even publicize the addresses - It can be maddening sometimes.
Also, if spam is not deleted, it could cause other problems for the ISP or the user, because they could be considered a spam host if not managed properly, and that could put a good ISP on a "blacklist" so spam needs to be dealt with in an appropriate manner, lest the account be unusable and the ISP is unusable because of spam - This is why appropriate spam protocols are needed, and as far as I know, most work well - but in order to work well, they have to be evaluated and changed as necessary and prudent.
What we need to do, and this is hard to do, is to try to put these spam operations down, but they are all over the place, and require a lot of patience, hard work, dedication, and skill - Spammers have different ways to get you, so most of the bad stuff has to be blocked by the ISP's. As System Admins figure one way to stop spam, the spammer is hard at work to try to circumvent the blocks - It's a tug of war that is hard to win.
Just My .02
Edited by **Brian**, 01 November 2008 - 12:01 PM.