getmxrr() performs an MX lookup on the specified hostname and returns TRUE on success. Arrays of the MX hostnames and weights are placed in the mx_hosts and mx_host_weights arguments. Both the mx_hosts and mx_host_weights arguments must be passed as references, as in &$mx_hostsand&$mx_host_weights. The weights indicate which MX host to try first, starting with the lowest value.
In addition to getting MX record information for a host, this function can also be useful for confirming the existence of an email address's domain name, regardless of whether it has an IP address.
<ul> <?php $host = 'yahoo.com'; getmxrr ($host, &$mx_hosts, &$host_wt) or die ("No MX records could be found for <i>$host</i>"); for ($ndx = 0; $ndx < count ($mx_hosts); $ndx++) $mx_host["$host_wt[$ndx]"] = $mx_hosts[$ndx]; ksort ($mx_host); foreach ($mx_host as $key => $val) print "<li><b>Host:</b> <i>$val</i> (Weight <i>$key</i>)<br>"; ?> </ul>
PHP Functions Essential Reference. Copyright © 2002 by New Riders Publishing (Authors: Zak Greant, Graeme Merrall, Torben Wilson, Brett Michlitsch). This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/). The authors of this book have elected not to choose any options under the OPL. This online book was obtained from http://www.fooassociates.com/phpfer/ and is designed to provide information about the PHP programming language, focusing on PHP version 4.0.4 for the most part. The information is provided on an as-is basis, and no warranty or fitness is implied. All persons and entities shall have neither liability nor responsibility to any person or entity with respect to any loss or damage arising from the information contained in this book.