[cobalt-users] Bounced back SPAM - Help is needed

["Isa Alemdag" <isa.alemdag@xxxxxxxxx>]

An guy who is using @mycompany.com as a SPAM sender and all the bounced back
emails are coming to our server. We have tracked down the IP address to
Netherlands and sent couple emails with all the details to abuse email of
www.hetnet.nl and www.planet.nl which seemed to be owner of the IP. Nothing
has done.

I also have a likely spammer email address which exchanged a few emails
asking about my clients etc. which I found totall unacceptable. The guy used
@hetnet.nl email address. So I made connection after finding our the spam
orgin.

My question is: if this company does nothing (maybe has an insider) abusing
our name and sending thousands of bounced back spam emails, what can we do?
Is there a way to stop receiving these bounced back emails if it's not
originated from our IP?

Your help will be highly appreciated.