I installed Postfix with ubuntu 9.10, apache2 and php5. I have an e-commerce website that sends out emails using the postfix installed on the server. Do I need to perform any special configuration on postfix to ensure out-going mail with sensitive information is secure?
I installed Postfix with the command
sudo apt-get install postfix
The PHP mail() function worked immediately afterwards, so I did not modify postfix's default configuration. Do I need to do more for security?