PHP mail setup on Bitnami UNIX (standard stack) for Dummies?

I've had a search around the forums and discovered a thread containing the following steps:

http://bitnami.org/forums/forums/mediawiki/topics/configuring-email

$ sudo /opt/bitnami/php/pear install Mail $ sudo /opt/bitnami/php/pear install Net_SMTP $ sudo /opt/bitnami/php/pear install Auth_SASL $ sudo /opt/bitnami/php/pear install mail_mime $ sudo apt-get install postfix

Which worked for that particular person; the only config settings I set after the postfix install were:

Mail configuration: ‘Internet site’ System mail name as ‘mydomain.com’

Everything else is working just fine but mail() errors if I try to use it. It's very difficult to get it to be descriptive with its errors.....

Any hints / further debug examples?

Thanks!

Iain