WordPress at a glance
filter is not described

comment_notification_headers filter-hook . WP 1.5.2

Filters the comment notification email headers.

Usage

add_filter( 'comment_notification_headers', 'filter_function_name_5612', 10, 2 );
function filter_function_name_5612( $message_headers, $comment_id ){
	// filter...

	return $message_headers;
}
$message_headers(string)
Headers for the comment notification email.
$comment_id(int)
Comment ID.

Changelog

Since 1.5.2 Introduced.

Where the hook is called

wp_notify_postauthor()
comment_notification_headers
wp-includes/pluggable.php 1634
$message_headers = apply_filters( 'comment_notification_headers', $message_headers, $comment->comment_ID );

Where the hook is used (in WP core)

Usage not found!