DNS-based Blackhole Lists are one of the most important parts of fighting spam, especially from the perspective of the user. The fact that listed entries can be queried via DNS makes the services quick and easy for mail servers to use, making it possible to display a filtered inbox without any noticeable effect on performance. The query method is easy to implement for developers and operators of email servers.
However, DNS services do come with a series of problems and difficulties, especially in terms being trustworthy and up to date. There is, for example, no guarantee that the entries in a DNSBL are justified and regularly updated by the DNSBL provider. Additionally, it’s often very difficult to remove addresses from the register of a DNS-based Blackhole List once they’ve landed on the list. Users of IPs that have been hacked in the past and used for spam will have a hard time rehabilitating their address.
If you regularly send large quantities of emails, you should consider a dedicated IP from a provider you trust, to keep the reputation of the address in your own hands and have a strong partner on your side should worst come to worst.