WPMU Change Email From Field

WordPress MU uses a PHP mailer function to send email. Therefore you have to change the setting in /wp-includes/pluggable.php. Unlike regular wordpress, where you can change the setting in wp-functions.php or wp-mail.php.

Edit pluggable.php

// From email and name
// If we don’t have a name from the input headers
if ( !isset( $from_name ) ) {
$from_name = ‘hidemeinsomeobscurefile’;