Cry about...
PHP Troubleshooting

Fatal error: Call to undefined function getmxrr()


The following message is generated when a PHP file (or one containing PHP) is viewed:

Fatal error: Call to undefined function: getmxrr() in D:\some\directory\some_file.php on line NNN

The actual directory given will vary. "NNN" identifies the line number in the file where the error originated.


The function "getmxrr" returns MX records corresponding to a given Internet host name. It is not implemented on Windows platforms (true for PHP up to and including 4.3 and possibly later versions as well.)

For further details and possible work around see

These notes are believed to be correct for PHP 4.3 running on Windows Server 2003 and may apply to other versions as well.

About the author: is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.