A question about Postfix.

Hello,
I installed Postfix on CentOS and my main.cf file is as below:
Code:myhostname = mail.my-example.com
mydomain = my-example.com
myorigin = $mydomain
## Uncomment and Set inet_interfaces to all ##
inet_interfaces = all
## Change to all ##
inet_protocols = all
## Comment ##
##- Uncomment ##
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
## Uncomment and add IP range ##
mynetworks = My Public IP, 127.0.0.0/8
## Uncomment ##
home_mailbox = Maildir/

smtpd_use_tls = yes
smtpd_tls_cert_file = /etc/postfix/mail.crt
smtpd_tls_key_file = /etc/postfix/mail.key
smtpd_tls_security_level = may
mynetworks_style = subnet
queue_directory = /var/spool/postfixWhen I want to send an email to Yahoo! then it show me below error:
Code:# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
ehlo localhost
220 mail.my-example.net.com ESMTP Postfix
250-mail.my-example.net.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
mail from:<info>
250 2.1.0 Ok
rcpt to:<myexample@yahoo.com>
554 5.7.1 <myexample@yahoo.com>: Relay access deniedI searched and find a solution as below:
Code:smtpd_recipient_restrictions = permit_sasl_authenticatedBut when I added it to main.cf then I can't do anything:
Code:# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
ehlo localhostHow can I solve it?

Thank you.