[Mimedefang] md is not the first relay

[Yizhar Hurwitz]

HI.

I have an MD installation that is behind another mail relay which I am 
not administaring.
As far as I understand, in that scenario, some DNSBL checks do not work,
for example checking if the email came directly from a dial-up connection,
as well as some HELO checks.

The configuration is:

internet ==> mailrelay1 ==> my mimedefang server ==> internal mail server.

How should I configure MD/SpamAssassin to use the HELO information from 
the top (or second?) "Received by" header?

Thanks
Yizhar Hurwitz