By "things" I assume you mean this stuff:
> ARPA: miw%uk.ac.man.cs.ux@cs.ucl.ac.uk > USENET: mcvax!ukc!man.cs.ux!miw > JANET: miw@uk.ac.man.cs.ux
miw is clearly Mario Wolczko's username.
Those will be his email address in different formats. The first would route email to him at miw@uk.ac.man.cs.ux using cs.ucl.ac.uk first as a gateway. The second address format is what's called a bang path, for UUCP email. The final one is a modern IETF standard email address. JANET is a network provider for UK academic institutions, similar to an ISP but structured differently.
You might find these references interesting:
https://en.wikipedia.org/wiki/Email_address http://www.faqs.org/docs/linux_network/x-087-2-mail.address.... http://www.livinginternet.com/e/ew_addr.htm