User Confirmation Emails going in "JUNK BOX"

[PAKIDIL]

this is the HEADER of the confirmation mail of the Vbulletin forums, and the mail is NOT sent to JUNK/SPAM
folder in Yahoo and hotmail:

Received-SPF: pass (google.com: domain of webmaster@vbulletin.org designates 209.62.16.134 as permitted sender) client-ip=209.62.16.134;
Authentication-Results: mx.google.com; spf=pass (google.com: domain of webmaster@vbulletin.org designates 209.62.16.134 as permitted sender) smtp.mail=webmaster@vbulletin.org


This is header info of my forums, where the mail is sent to JUNK/SPAM of yahoo and hotmail:

Received-SPF: neutral (google.com: 66.90.101.244 is neither permitted nor denied by domain of zahidonly_4u@yahoo.com) client-ip=66.90.101.244;
Authentication-Results: mx.google.com; spf=neutral (google.com: 66.90.101.244 is neither permitted nor denied by domain of zahidonly_4u@yahoo.com) smtp.mail=zahidonly_4u@yahoo.com


So can anyone tell how to fix this, so that my FORUMS do not send the mail to JUNK/SPAM of yahoo and hotmail ?