Bear in mind two things: the email address could be fictitious or belong to an innocent bystander; the IP address could belong to anyone with an infected or compromised machine and again be owned by an innocent bystander. I generally check using senderbase which in this case presently shows no conventional spam.
You can always email postmaster@ the domain who owns the IP address though - that should always reach an admin.
I see we now have a simple arithmetic challenge and a low-tech captcha at signup.
How 'bout this: I move these posts about spammers to a sticky, call it something like "What we do to spammers", and also publish the list of spammers we've kicked out, along with their email and IP addresses and what abuses they're guilty of! Actually the list would be far too long, but just showing the last moth's worth should be adequate to make them think twice before offending again. They'll find themselves banned here, but maybe other forums will pick up this tactic and make the price for spamming too high.
Ok, here's the last spammer who just posted, on this topic no less (and others), and I deleted his posts and kicked him out and banned him within just a few minutes of when he posted: (ab)user name: doldglarl email addr: dariosoon23@prokonto.pl IP addr: 188.138.116.162 If any one wants to make him extra sorry he posted his trash here, be my guest!
Probably no point in listing them. The email address will be a randomly generated and the IP address is probably for a hijacked machine in a bot network.