[dns-operations] When TLDs have apex A records

[Francis Dupont]

 In your previous mail you wrote:

   I'm not quite sure I understand all the problems you're describing
   here, but you may want to consider implementing something we had when
   I was DNS admin at Yahoo!. All of our critical A records had MX
   records associated with them. The ones that were not supposed to
   receive mail were directed to a mail server that did nothing but
   bounce messages sent to it with a message that said basically, "This
   host is not supposed to receive mail." (Sorry I don't recall the error
   number or the configuration, that was handled by our mail guys.)
   
=> 521 (cf RFC 1846)

Francis.Dupont at fdupont.fr