[exim] The Bleeding Edge of Snapshot Features in Use

Here's one of the things I'm doing with the new bleeding adge snapshot
features.

The following code is in my system filter file. What it does is look up
a bunch of "information" and puts it in a header. Then it goes into spam
assassin where the bayesian filter looks at this information and has
more data to work with. Then the message comes back to Exim where the
extra header information is removed. I'm doing a lot of extra headers
like this and it really helps. So - just to let Phil know how we are
actually using the features we request.

Thanks Phil

headers add "X-Sender-Nameserver: ${sg{\
${lookup dnsdb{zns=${sg{$sender_host_address}\
{\\N([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3}\)\.([0-9]{1,3}\)\\N}\
{\\N$4.$3.$2.$1.in-addr.arpa\\N}}}} \
${lookup dnsdb{zns=${sg{$sender_host_address} \
{\\N([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3}\)\.([0-9]{1,3}\)\\N}\
{\\N$3.$2.$1.in-addr.arpa\\N}}}} \
${lookup dnsdb{mxh=$sender_address_domain : ${domain:$h_From:} :
$sender_helo_name}} \
}{\n}{ }}"