SpamCop FAQ : SpamCop Mail Service : FAQ about Filtering and Held Mail :
If a message matched a whitelist entry, that will be documented in a message header X-Whitelisted:
If there is no X-Whitelisted header, then the message wasn't on the SpamCop blacklist (or whichever blacklists you have selected)
For more detailed information on Held Messages and headers etc. see
Why did this message get held?