I spoke with someone today whose email is not reaching his intended recipients. He works for a small company. They handle their email on their own server. They noticed a while ago that their messages were bouncing back to them – rejected. They had been blacklisted.

So what does that mean?

There are organizations on the Internet who track spammers and potential spammers on blacklists. Internet service providers subscribe to these lists and refuse to carry messages from people on the list (tracked by the IP address used by their mail server). This is one way ISPs try to thwart spam and viruses.

One problem is that potential spammers are unaware of their status – because they aren’t really spammers; they are often small organizations who handle their own email and have left open a back door to their server. A spammer can sneak through this backdoor and send email out through the server without the company knowing. (This might happen to your ISP too – though they should know better.) Once this error has been detected they may be added to the blacklist.

What can you do?

If you suspect that you have been blacklisted or want more information – you can check out MAPS at http://www.mail-abuse.com/enduserinfo.html. Their web site walks you through the process of checking to see if you have been blacklisted, gives advice to remedy the situation, and instructs you on how to request that your IP address be removed from the blacklist once you have repaired your server.

Thankfully I have not had to deal with being blacklisted. I have heard that the folks to maintain these lists are very helpful if you are in earnest about clearing your good name. I do keep the blacklist in mind when I’m selecting an email provider – some cheap ones taint their name by selling accounts to spammers and that’s how they get on the list. I might research a provider by doing a search for their name + blacklist. If an ISP has made this mistake you can bet someone has mentioned it in a newsgroup.