Forum Moderators: not2easy
And even if they did, it seems unlikely that they will have registered the email at the Copyright Office, meaning that the most they could force you to do is take down the message....
A spammer just isn't likely to come after you.
Publishing private emails has a couple of other problems--you're violating someone's privacy, which might (I don't know for sure) be against the law in some places. And you're possibly annoying your friend, which seems to me to be the most important thing.
But from your message I'm guessing that you are from the UK, not the US, so you should check and see if the rules are different. If anything, they are probably more stringent.
As a general rule, I wouldn't publish people's emails without permission.