Imap::selectOutgoingMessageIdFromHeader

protected function selectOutgoingMessageIdFromHeader($message)
{
	if (preg_match('/X-Bitrix-Mail-Message-UID:s*([a-f0-9]+)/i', $message['BODY[HEADER]'], $matches))
	{
		return $matches[1];
	}
	else
	{
		return false;
	}
}