I've installed ubuntu server 12.04 with linode.
What do i need to install to allow my application to be able to send email in and out? Or is this package natively setup with ubuntu 12.04?
Figured this out. I tailed the apache log and it indicated that /usr/bin/sendmail was not found.
In order to fix this, you just need to install exim:
sudo apt-get install exim4-daemon-light mailutils; dpkg-reconfigure exim4-config
Source: Linode