[vidarh]

The big providers are actually less of a problem when it comes to RBLs than smaller ones, as the big providers have their own filtering and/or rely on reputable RBLs. The bigger problem in my experience is companies with overzealous IT people with the authority to largely do as they please, where you get some percentage that pick their favorite set of block lists with no consideration for whether or not said block lists are properly run.

We occasionally get on block lists, and though we do get onto reputable block lists now and again after mistakes by users, they're rarely a problem and quick to get off. But now and again we get on some shady block list where there's no quality assurance, and where delisting procedures are onerous. Every now and again one of them is an outright money-making scam ("pay $99 for express delisting, or wait for X days for the regular service; oh by the way we just randomly added you with no basis")