So use an SMTP relay service for outgoing mail. Most of them even have free tiers. I've been using one with a dynamic IP for years, albeit one where the IP does

So use an SMTP relay service for outgoing mail. Most of them even have free tiers. I've been using one with a dynamic IP for years, albeit one where the IP doesn't change often. On the receiving end I use a super inexpensive spam filtering service too, MX Guard dog. If my IP suddenly changes then it queues up mail until host resolution succeeds again.