Description:
------------
I have a "Warning: mail(): Erreur d'appel #1.5 in ..." with 
the function mail() when I try to send an e-mail to this 
sort of address : xxx_@xxx.xxx but I dont know why. if I 
try this : xxx_x@xxx.xxx it is ok, but I have an address : 
myname_@hotmail.com and the "_@" create a bug.
What can I do to send an e-mail to xxx_@xxx.xxx without a 
calling error #1,5 ?

Sorry for my poor english, I am french. ;)

Reproduce code:
---------------
<?
mail($to, $subject, $message,$from);
//where $to = "mynane_@hotmail.com"
// $subject a subject
// $message a message
// $from an address
?>

Actual result:
--------------
Warning: mail(): Erreur d'appel #1.5 in ...