comment_notification_headers filter-hook . WP 1.5.2

Filters the comment notification email headers.

Usage

add_filter( 'comment_notification_headers', 'filter_function_name_2364', 10, 2 );
function filter_function_name_2364( $message_headers, $comment_id ){
	// filter...

	return $message_headers;
}

$message_headers(string)

Headers for the comment notification email.

$comment_id(int)

Comment ID.

Where the hook is called

$message_headers = apply_filters( 'comment_notification_headers', $message_headers, $comment->comment_ID );

Where the hook is used (in WP core)