When forword Email to Yahoo account have some problem & return ,
is Yahoo setting security are so high , this is the following information :
http://www.ahfx.net/weblog.php?article=107

When use Netvigator SMTP Server to send email delay problem is Netvigator some
mail server are backlisted , this is the following information :
http://www.geoexpat.com/forum/thread8805.html