I don't know about countries outside the US but one can always look into it. Well, you can figure this out. Forget Their Email Server Don't try messing with the email server of the junk email offender. More than likely, the email server will add your name again to it's mailing list and you will end up receiving duplicate junk email messages. I suspect most losers don't know how to set up an email server properly.
Any idiot can spam the Net though.
The Consequences You will probably get a nice email message back from someone in charge who will tell you the loser's account has been closed, the loser has been warned, they are looking into it, very sorry, etc. Complaints that bounce back from the loser's account is evidence that his mailbox is full or his account is closed due to other people sending email complaints just like you. Many losers have had their account closed literally within hours of the spam. Their reputations tarnished forever on the Net. These are the lucky ones.