Sites such as https://www.dan.me.uk/dnsbl then help people do this.
That site in particular may "warn":
> This DNS blacklist contains ALL tor nodes (entry, transit and exit nodes) - think carefully before choosing to use this list for blocking purposes.
but anyone who doesn't understand tor simply won't understand the decision and choose ALL.
Running a relay on your own address isn't sensible because of this. Nevermind an exit node.