This is generally a whitespace problem with the confirmation codes in Mailhost configuration emails, in that some ISPs email and webmail servers are adding whitespace they shouldn't be adding, which causes problems with both parsing and Mailhost configuration. Please make sure that you are returning the configuration emails (and submitting your spam) EXACTLY as sent. Thanks!

Security Consideration and Warning:
Each configuration email specifically states "Do not post this email in
public. It contains confidential information related to the security of
your SpamCop account." Violations will be dealt with by SpamCop Admins.