[Mimedefang] Darknet as last MX

[Kenneth Porter]

The topic comes up occasionally about whether to list some kind of bogus 
value as one's lowest-priority MX. I just saw this interesting thread on 
SlashDot about the use of "darknets" to track suspicious network activity, 
which reminds me that I'm using a darknet address for my last MX entry:

<http://developers.slashdot.org/developers/04/06/07/2123245.shtml>