I have setup a multiserver in Debian Squeeze. A client of mine is using a php script to send an email of a form to himself when some one fills it out on his site. The e-mail never arrives in his mailbox. I am assuming this is because either my web server has no mail capabilities or it doesn't know where my mailserver is. How do I go about rectifying this, I had a look in /etc/php5/apache2/php.ini and saw that under the mail section it said that my smtp server was localhost which I change to my mail server, is there anything else that I need to do to get it to work. Please advise as this client needs it working urgently.