diff --git a/wp-mail.php b/wp-mail.php
index 40550c0cbd..9d09d6826d 100644
--- a/wp-mail.php
+++ b/wp-mail.php
@@ -10,8 +10,8 @@
 /** Make sure that the WordPress bootstrap has run before continuing. */
 require(dirname(__FILE__) . '/wp-load.php');
 
-if ( is_multisite() && ( !defined( 'POST_BY_EMAIL' ) || !POST_BY_EMAIL ) )
-	die( __( 'This action has been disabled by the administrator' ) );
+if ( ! apply_filters( 'enable_post_by_email_configuration', true ) )
+	wp_die( __( 'This action has been disabled by the administrator' ) );
 
 /** Allow a plugin to do a complete takeover of Post by Email **/
 do_action('wp-mail.php');