I have a feeling that these are the same people responsible for the "domain registry of canada" scam. They would mail (snail mail) "invoices" for domain renewals, which in fact were solicitations to move domains to their VERY expensive service (typically $35-$100 per year per domain). The "invoice" always came in a brown government style envelope, with the usual red printing and a Canadian flag... it was a total, complete, and overwhelming scam.
example:
http://support.easydns.com/domain.slammers/droc.php
BTW, Linkster, the address they give is a mailboxes etc / UPS store... what have I said before about people using those things to hide?
Good luck on tracking them down... I wouldn't be surprised if the MBetc just redirects the mail somewhere else (which is an option on their services...)
Alex