'Delete an MX record matching name and identifier from this
Zone.  Returns a Status object.
If there is more than one match delete all matching records if
all is True, otherwise throws TooManyRecordsException.'

def delete_mx(self, name, identifier=None, all=False):

    name = self.route53connection._make_qualified(name)
    record = self.find_records(name, 'MX', identifier=identifier, all=all)
    return self.delete_record(record)
