Real-time Black Lists or RBLs Explained

Realtime black lists are web site services that keep track of the domain name or ip addresses where possibly the spam emails originate from. The purpose behind the service is to allow IT Mail Administrators to query the database and block messages that are listed in there in order to block spam. There are scores of websites that offer this type of service and most of them provide the service at no cost.

If your IP address is listed in an RBL then the chances are that the emails that you send from your network to your clients can get blocked even though it may not be spam. Most anti-spam filters query RBLs and if your IP address is listed in one of the RBLs then these filters may not allow your e-mails to go through and block them as spam.