Dealing with blacklists
Al has a good post listing the top 5 things senders should remember when dealing with blacklists.
One of the critical things to remember about blocklists is that they are an early warning sign. Sure, some of them are one crank and his cat and will not hurt your overall delivery. A sender may be listed for totally spurious reasons . On the other hand, many of the widely used public lists and the private lists at the big ISPs, list IPs that they see as doing something wrong.
The challenge for anyone listed on any IP based blocklist is to look inside and determine what it is that they’re doing that caused the listing. The first step is to look at the technical issues, does your mail look like something coming out of infected bots? Is there a configuration problem? If the answer is no, then senders have to look at their practices. Are they sending mail to people who don’t expect it? Are they sending mail to people who didn’t ask for it? Most listings that will affect large numbers of recipients fall into the above 2 categories: technical or practices.
Technical problems can be fixed easily, once they’re identified. Permission or practice problems can also be fixed, but may require a sender reassess how they are using email and what value email brings to the business.