Which E-Mail Address is Reported to ISPs?

I use the Email Submission System to forward
spam to SpamCop. I note from SpamCop FAQs that
"All spam reports include a valid email
address for you". I'd be grateful if anyone
could tell me which address this is - the
e-mail address I've registered with SpamCop
or the sender's address from the e-mails
which I use to submit spam?

Thanks in advance.

Dick K