We have stopped checking this blakclist as its free list does not allow commercial use. It is active and unfortunately you must manually check this list.
V4B is from Florida US and is dedicated to maintain a SMTP IPv4 DNS block list. It provides two lists, one pay-for-use list and another free to use list. The lists are automatically generated by their custom programming.
You can remove your IP from this list but they ask for a correct RDNS record.
Is the information on our site wrong or incomplete? You don't want us to monitor your blacklist? Or do you operate a similar blacklist? We would like to hear from you!