Bootstrap: do not go gentle into that good night r38411, r38412, and parts of r38389.

See #36335.

Built from https://develop.svn.wordpress.org/trunk@38470


git-svn-id: http://core.svn.wordpress.org/trunk@38411 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-mail.php

@@ -21,6 +21,9 @@ if ( ! apply_filters( 'enable_post_by_email_configuration', true ) )
  */
 do_action( 'wp-mail.php' );
 
+/** Get the POP3 class with which to access the mailbox. */
+require_once( ABSPATH . WPINC . '/class-pop3.php' );
+
 /** Only check at this interval for new messages. */
 if ( !defined('WP_MAIL_INTERVAL') )
 	define('WP_MAIL_INTERVAL', 300); // 5 minutes