On Fri, 19 Oct 2007, Renaud Allard wrote:
| I am trying to determine if a blacklist of IP of MXes (not containing the IP
| sending the spam, but the IP of the MX) exists, and if it would be useful to
| have such a blacklist.
Some time ago, for what it's worth, we used such blocks occasionally.
We added the IP to a file referenced via "ignore_target_hosts", so the
spams in question would therefore fail sender verification.