You can self-host the receiving side of your mail server (with spam filtering etc.), but send all your mail through a mail provider with a good reputation. Conf

You can self-host the receiving side of your mail server (with spam filtering etc.), but send all your mail through a mail provider with a good reputation. Configure your own SMTP server to use that other server as a relay, you can even do your own DKIM signing before sending off your mail. At least then you shouldn't have a problem with IP reputation.