In the past our domain was blocked by one of the top free email providers - we sent about 1 email per day at the time - because we sent email from an IP owned by a hosting provider who also owned another IP that in the past had sent spam. That was the reason given. Whitelisting and adding as a contact didn't allow us to even receive emails from ourselves, to our own email address (over a decade old at the time) with that provider. Our _domain_ has never had spam sent from it, never appeared in a blacklist, and the IP address itself was clean.

So yes, own the IP [and do all the regular SPF, DKIM and such], but be aware that is possibly nowhere near enough.