[Herts] Of Blacklists and Clamav!

[nicolas]

Hi,

For a while now I have been receiving email on jetblackjelly.com (My
blade server out on the internet) then smtp forwarding it to
beijingblack.dyndns.org, a centos box on my home network where ASSP,
clamav etc are used to remove sundry nasties.
This setup was only intended as an interim step, prior to getting ASSP
etc loaded on the blade. But it has now been in use for a while.. 
On Saturday morning no email appeared to be getting delivered to
beijingblack it was all getting bounced back to the sender as follows

>			The Postfix program
>
><nicolas at beijingblack.dyndns.org> (expanded from
><nicolas at jetblackjelly.com>):
>     host beijingblack.dyndns.org[82.9.68.130] said: 550 5.7.1
Blacklisted 
>by
>     db.gb.clamav.net  (in reply to MAIL FROM command)

Hmm. I checked my host jetblackjelly.com with
http://www.mxtoolbox.com/blacklists.aspx and it does not appear to be on
any blacklists - Phew. I have now amended my configuration so that email
is collected directly from the blade and that is working OK. But of
course all the spam is back.
Of course I would expect the dynamic address to be blacklisted, although
it never sends so that should not matter? But I am still not "quite"
sure what is happening.  

Any thoughts? 

Regards
Nicolas