If your ISP requires SMTP AUTH to send out email then you need to add following lines to main.cf:
Code:
relayhost = smtp.yourispmailserver.com
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/etc/postfix/smtp_passwd
Put SMTP username and password in /etc/postfix/smtp_passwd
Code:
smtp.yourispmailserver.com username:password
Build hash table (in /etc/postfix/ directory):
Code:
cd /etc/postfix/
postmap smtp_passwd
Restart postfix.