Marius Gologan skrev den 2014-05-14 17:21:
This should help you discover most (not all) IP ranges in cidr format:
host -t txt outlook.com | tr " " '\n' | awk '/\./' | sed
"s/include:\|ip4://g" | sort -u | grep -i "[a-z]" | while read record;
do
host -t txt $record ; done | tr ' ' '\n' | awk -F ":" '/[0-9]*\.[0-9]/
{print $2"\tpermit"}' | sort -u
missing ip6 mx a aaaa
but the basic are there :=)
if one make a spf tool that list all ips pr sender domain in a easy
parselble form it would be nice to see, use spf as safe source for the
cidr list to postscreen
