[Mimedefang] How to block based on bad dns resolution names?

[David Fowler]

Here's one that I would love to crush, filter, destroy:

Received: from smtpikdpivfmvm02w.worldwidemailserver.com (localhost
[203.210.222.130] (may be forged))

The part that yanks my chain is the "resolved localhost".  Nslookup returns
the same result.

I would like to reject the connection like I do for localhost and numeric
IPs in the HELO.

Is there a variable for this that I can filter on?  I'm getting a little
punchy looking for it.  This isn't an isolated case either.  I have caught
11 different IPs doing this in the 203.210 segment alone, and none of them
were sending legitimate email.

Any help would be appreciated.

David Fowler