SPF checks

Sender Policy Framework

Authorized relay hosts for a domain in DNS TXT record
   "v=spf1 a mx a:lists.ssc.com include:zgp.org ?all"

Download the ACL into /usr/local/etc/exim
   cd /usr/local/etc/exim 
   fetch http://spf.pobox.com/exim4.spf.acl-2.03.txt

Install Mail::SPF::Query (v1.9.7+)
   perl -MCPAN -e 'install Mail::SPF::Query'

Run spfd
   /usr/local/bin/spfd -path=/tmp/spfd -setuser=mailnull -pathuser=mailnull -pathgroup=mail -pathmode=0660 &

As of 2004-01-08 spfd has not been updated in the perl module package...may need to download from http://www.credentia.cc/misc/spfd