vps php mail marked as spam | shared php not marked as spam

[kc8yds]

hi, anyone ever run into this?

this code:

<?php

mail(
'myEmail@yahoo.com'
,
'mySiteName Confirmation'
,
'(confirmation link)'
,
'From: mySiteName <confirm@mySite.com>'."\r\n".
'Reply-To: myName <myName@mySite.com>'
);

?>

when sent from a vps (centos 5 / interworx) gets marked by yahoo as spam but if sent from steadfast shared hosting it does not get marked as spam

now i could always just send email out from the shared account and use the vps for the sites but i would rather try and keep everything at one place so if anyone has ever ran into it i would appreciate if you could help