For example, AOL once blocked all incoming mail from Earthlink users because the filtering software judged all posts from earthlink.net to be spam. AOL is not the only overachiever, however. As recently as last week, I received a note from a frustrated reader who discovered that MSN Web TV was blocking all e-mail from his ISP, SBC Pacific Bell. He complained to Pac Bell that the Web TV mail server was rejecting his sbcglobal.net e-mail to his brother. After numerous calls, the best answer he could get was, "It's only a problem if you want to e-mail someone at a WebTV address."

Individual users, unfortunately, cannot do much about an ISP's overkill efforts to control the spam. However, there are some measures consumers can take to stem the flow of spam to their own mailboxes. First and foremost is to guard your primary e-mail account and do not give out this address online or in writing. Millions of e-mail addresses are traded daily from sources you'd never suspect. Set up a secondary Web-based mail account, such as Yahoo! or Hotmail. You can check this account periodically or more often if you're expecting a particular post, such as an airline confirmation.

Second, explore the many anti-spam products available to determine which is best for your system. I use SpamNet by Cloudmark and am thrilled with how well this free product catches and isolates the incoming spam. Each time mail is delivered, SpamNet scans the Inbox and moves any suspicious posts to a folder labeled Spam. I check the Spam folder to ensure all posts are in fact bogus and then delete all the contents at once.

SpamNet installs an additional toolbar within Outlook with buttons labeled Block and Unblock. These buttons allow the user to report any offending messages to Cloudmark that were missed by SpamNet's scrutiny and unblock messages that were sent to the Spam folder in error.

Since installing SpamNet, it has intercepted and correctly identified nearly 90 percent of all incoming spam. One morning, out of 28 incoming messages, 26 went to the Spam folder. This product is specifically configured to work as an add-on to Microsoft Outlook 2000 and Outlook XP. A version for Outlook Express is currently in development.

SpamKiller by McAfee is a commercial product ($25) that supports a wider variety of e-mail programs, such as Outlook Express, HotMail, Netscape Mail, Groupwise and Eudora. It does not support AOL or Yahoo Mail at this time.

Unlike SpamNet, which compares messages to a known blacklist of spammers, SpamKiller uses pre-set filters to sort out junk e-mail. SpamKiller has an intuitive interface that locates your existing mail program during setup and automatically ignores anyone in your address book as a spammer.