I transferred my science site and mailing list to Digital Ocean, and a few weeks ago found it suddenly overtaken by a growing block-range blacklist by MIPSpace. Much of Digital Ocean's IP address range is now blacklisted by MIPSpace, which certainly degrades my ability to send mail.

Digital Ocean's reply to this:

----------- At this time we are not sure if we can get this block removed. Mipspace does not email abuse and anyone can say an ip is bad and eventually they block the entire range.

At this time only a small % of our ip space is effected, nyc1 is the only location we offer that has less than 10% of all ip space on this list.. Personally, I would move to nyc2 if possible and reconsider who you email and what you email. They don't even follow quarantine removal processes. We're sorry we cannot accommodate your needs but will be more than happy to refer you to services that can relay to almost everyone in the world. -----------

So on the one hand I understand their position; MIPSpace is a bad actor from what I've read. On the other hand Digital Ocean are in the business of renting IP addresses, with the implicit understanding that they are responsible for ensuring that this sort of block-level blacklisting isn't happening for addresses they rent out.

It is a frustrating situation all round for people like myself, who carefully manage our email and play by the rules, to be stepped on in this way by a combination of parties and bad incentives.