On Tue, Feb 22, 2011 at 04:37:03PM -0500, David Sparro <dsparro at gmail.com> wrote a message of 24 lines which said: > it is up to the application how it will use the data. MX records are only used by MTA and, no, it is NOT up to the MTA to decide how to handle MX records, there is a standard for that, RFC 5321, section 5.1.