include_once(XOOPS_ROOT_PATH.'/language/'.$GLOBALS['xoopsConfig']['language'].'/mail.php') [line 35]
include_once(XOOPS_ROOT_PATH.'/language/english/mail.php') [line 37]
include_once(XOOPS_ROOT_PATH."/class/mail/xoopsmultimailer.php") [line 44]
The new Multimailer class that will carry out the actual sending and will later replace this class.
If you're writing new code, please use that class instead.