SMTP :: booleandelto ( [ string address ] )
Returns TRUE if has been successfully deleted, FALSE if not.
string address default value are: all
string address possible values are: all, user@hostname address format
Example:
$mail = new SMTP;
$mail->AddTo('user@domain.net');
// delete only user@domain.net from To
$mail->DelTo('user@domain.net');
// also, you can delete all To addresses
$mail->DelTo();