EMail sending problem

While i am sending emails usign php why my mail is goign in spam folder and not in inbox of yahoo?

 

if you are using shared hosting one of the other sites sharing your ip address may have been placed on yahoos spam list.

 

Make sure you set the from, message-id and content-type mail headers.

 

Set up SPF and Domainkeys and sign all messages sent.

If they absolutely need to be delivered, use something like Sailthru (google it).

 

set your mail headers.
php.net/mail.