There definitely should be a way to block any emails from the domain(s) they're coming from. That option will be part of your email account provider (hotmail, gmail, yahoo, whatever you have). In Hotmail I remember it's something like Account Options > Email > Safe and Blocked Senders > Blocked Senders and that brings you to a page where you can type (or paste) a domain name (@example.com) or email address ([email protected]
) so the emails no longer come to your inbox. I haven't had to block any senders since switching to Gmail, but I imagine blocking senders would be much the same everywhere.
I hope this helps, feel free to ask anymore questions and I'll do my best to help.