Like IgnoreMailFrom and IgnoreHosts create two entries that will override the policy if the email also contains a List-id: or list-post: header denoting an email from a mailing list.
Suggested names:
IgnoreMLMMailFrom
IgnoreMLMHosts
For instance adding the IPs into IgnoreHosts of Google infrastructure to be able to accept emails from googlegroups is a very broad sword, while it is only needed to override when it is a google group post (containing a list-id: header)
Planned for next major release.