I've been trying to configure the zen mailhosts, but spamcop hasn't seen all mailhost aliases for zen.

For instance if you compare the mx records for zen.co.uk (as seen at http://www.robtex.com/dns/zen.co.uk.html) with the standard "Zen Internet" mailhost config in spamcop, some servers are missing.

For instance, the lack of the following server is preventing me from submitting some spam:

212.23.6.48 bastion02.mail.zen.net.uk

While I have tried to force other mail server in the pool to register, by sending multiple e-mails, the only server spamcop registration e-mails pass through is bastion01.mail.zen.net.uk

You will need to send an email to service[at]admin.spamcop.net with "mailhosts" in the subject line and be sure to include your account name; as this is outside the scope of what can be handled in this forum.
For more information about the subject see: Mail-Host Configuration of your Reporting Account

I added that to the Zen Internet (11196) Mailhost.

Try reporting your spam again.

It would still be a good idea to send me your login email address so I can review your account details. Do not post your email address here in public.

- Don D'Minion - SpamCop Admin -
service[at]admin.spamcop.net