Thanks for the replies!
So if I have an affiliate that joins my website's "affiliate program" and they spam a bunch of email addresses from their own IP address promoting the affiliate ID URL link I provide to each affiliate I would have to worry about this affiliate spammer getting my IP address blacklisted? or just my domain name?
I'm guessing they wouldn't be able to blacklist my IP address because the emails that were sent came from their own IP address, but I'm just wondering if a domain name can be blacklisted?
Because when I check on mxtoolbox.com it looks like it looks up the IP address and not the domain name.