Please help..how to set mailbox yahoo on 7650!!!

If you don't have pop3 access(i.e you don't pay for e-mail) you can use the Services(aka wap browser) to access your y! mail. address is http://wap.yahoo.com

No need to pay anything. My settings which work properly:

Access Point: a1.net (that of your phone company)
Mail address: Your Yahoo-Address
Outgoing Mail Server: smtp.mail.yahoo.com
Username: like mail-address, without @yahoo...
Incoming Mail Server: pop.mail.yahoo.com
Mailbox: POP3
Security, Secure APOP-Login: off

Sorry, one correction:

Outgoing Mail server: smtp.a1.net (again that of your phone company!)

Without this, u can check your mailbox, but not send mails with this mailbox.

yahoo allows you to use their outgoing mail server at smtp.mail.yahoo.com to send outgoing mail. but your email client needs to be able to login with your userid and your password. not all mail clients support logins and passwords for outgoing mail.