In practice, while there are some services which will purport to tell you an IP's reputation, their output isn't well correlated with actual delivery outcomes a

In practice, while there are some services which will purport to tell you an IP's reputation, their output isn't well correlated with actual delivery outcomes at scale (depending, to some extent, on what domains you're sending to). This is because the big consumer mailbox providers often don't rely on public datasources for assessing reputation, and because reputation is tracked at the domain level, in addition to - or sometimes instead of - the IP level. For example, there have been some indications from Gmail that they no longer use IP reputation at all, starting a year or two ago. And re: blacklists: +1 to Spamhaus, but in practice it's one of very few blacklists that have meaningful impact to net delivery.