gistfile1.php

<?php
if ( ! function_exists( 'wp_new_user_notification' ) ) :
	function wp_new_user_notification( $user_id, $plaintext_pass = '' ) {
		
		// Return early if no password is set.
		if ( empty( $plaintext_pass ) ) {
			return;
		}
			
		$user 	    = get_userdata( $user_id );
		$user_login = stripslashes( $user->user_login );
		$user_email = stripslashes( $user->user_email );

		// The blogname option is escaped with esc_html on the way into the database in sanitize_option
		// we want to reverse this for the plain text arena of emails.
		$blogname = wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );

		$message  = sprintf( __( 'Username: %s' ), $user_login) . "\r\n";
		$message .= sprintf( __( 'Password: %s' ), $plaintext_pass) . "\r\n";
		$message .= wp_login_url() . "\r\n";

		wp_mail( $user_email, sprintf( __( '[%s] Your username and password' ), $blogname ), $message );

	}
endif;