> nobody knows where to send a message until you setup your MX records Not quite. RFC 974 says It is possible that the list of MXs in the response to the q

> nobody knows where to send a message until you setup your MX records Not quite. RFC 974 says It is possible that the list of MXs in the response to the query will be empty. This is a special case. If the list is empty, mailers should treat it as if it contained one RR, an MX RR with a preference value of 0, and a host name of REMOTE. (I.e., REMOTE is its only MX). In addition, the mailer should do no further processing on the list, but should attempt to deliver the message to REMOTE.