OK - here's the latest version of my code that separates the main domain
part from a host name. It depends on my rb.junkemailfilter.com DNS
lookup. I now have it running on 2 servers.
# Separates the domain part of a hostname -
ftp.perkel.com returns
perkel.com
# DNS lookup returns 127.0.0.1 for single level domains
# DNS lookup returns 127.0.0.2 for two level domains
# DNS lookup returns 127.0.0.3 for three level domains
warn !condition = ${if eq{$sender_host_name}{}}
dnslists = rb.junkemailfilter.com/$sender_host_name
set acl_c_rb = $dnslist_value
warn condition = ${if eq{$acl_c_rb}{127.0.0.1}}
set acl_c_sender_host_domain = ${sg{$sender_host_name}\
{\N^.*\.(.*\..*)$\N}{\$1}}
add_header = X-Sender-Domain: $acl_c_sender_host_domain
warn condition = ${if eq{$acl_c_rb}{127.0.0.2}}
set acl_c_sender_host_domain = ${sg{$sender_host_name}\
{\N^.*\.(.*\..*\..*)$\N}{\$1}}
add_header = X-Sender-Domain: $acl_c_sender_host_domain
warn condition = ${if eq{$acl_c_rb}{127.0.0.3}}
set acl_c_sender_host_domain = ${sg{$sender_host_name}\
{\N^.*\.(.*\..*\..*\..*)$\N}{\$1}}
add_header = X-Sender-Domain: $acl_c_sender_host_domain