include/class.ticket.php, approx. line 517 - 526
//If enabled...send alert to staff (New Message Alert)
if($cfg->alertONNewMessage()){
$sql='SELECT message_alert_subj,message_alert_body FROM '.EMAIL_TEMPLATE_TABLE.' WHERE cfg_id='.db_input($cfg->getId()).' AND tpl_id='.db_input($cfg->getDefaultTemplateId());
$resp=db_query($sql);
if($resp && list($subj,$body)=db_fetch_row($resp)){
$subj = str_replace("%ticket", $this->getExtId(),$subj);
$subj = str_replace("%subject", $this->getSubject(),$subj);
$subj = str_replace("%email", $this->getEmail(),$subj);
include/class.ticket.php, approx. line 994 - 1003
//If enabled...send alert to staff (New Ticket Alert)
if($alertstaff && $cfg->alertONNewTicket() && is_object($ticket)){
$sql='SELECT ticket_alert_subj,ticket_alert_body FROM '.EMAIL_TEMPLATE_TABLE.
' WHERE cfg_id='.db_input($cfg->getId()).' AND tpl_id='.db_input($cfg->getDefaultTemplateId());
$resp=db_query($sql);
if($resp && list($subj,$body)=db_fetch_row($resp)){
$subj = str_replace("%ticket", $ticket->getExtId(),$subj);
$subj = str_replace("%subject",$ticket->getSubject(),$subj);
$subj = str_replace("%email",$ticket->getEmail(),$subj);
The above code adds the %email field to New Message Alert and New Ticket Alert Email Subjects. The above fix may not be particularly useful to You in the long run. Why not have Your (from field contain fancy information)?