So, you think you've received spam (unsolicited mail) from this domain?
Let me make one thing absolutely clear. I don't send spam. I don't let anyone else send spam using my equipment or resources. What we have here is impersonation.
But you have received a mail (probably several) with an address purporting to be from here.
I am located in the UK, I use NTL as my ISP, and clarkgroup.co.uk is hosted by Hurricane Electric (Fremont California). Any real mail from me will have been routed from one of these locations.
The "from" address in emails is completely controlled by the sending email program! The ISP has no control on what you write in here. You could quite easily write mails that seem to be from "firstname.lastname@example.org" and anyone not familiar with how email works and how to read email headers would be non the wiser.
The only way to check if an email comes from who you think it does is to check the full email header. This shows the route taken by the mail across the Internet. The first location will usually also be faked, but once the mail has left the spammer's network, the addresses become real. You can usually then determine which ISP they are using, and thus where in the world they are located.
People don't know this, which is why they program their email servers to "bounce" messages back to the sender. The sender is usually faked for spam messages, so the poor impersonated person (me) gets a tsunami of "failed to deliver your message" messages! If your server does this, then please stop it. You are adding to the bulk of useless mail in the Internet.
Why me? Well, one way that email server check mails for validity is to confirm the sending domain name is real. clarkgroup.co.uk is real, so that fools that test. At some point in the past, some criminal has scraped the "whois" data from Nominet (the UK registry of domain names) and is using those names as fake spam sources.
If anyone knows if sending emails using a faked "from" address is
any laws, tell me! Then I'll sue the &^%&^&^%s.