How to send email on Mac OS X 10.8

Today I configure Ruby on Rails to send email (don't use SMTP) but I get error message below

send-mail: fatal: chdir /Library/Server/Mail/Data/spool: No such file or directory

To fix it, open terminal

sudo mkdir -p /Library/Server/Mail/Data/spool
sudo /usr/sbin/postfix set-permissions
sudo /usr/sbin/postfix start

Cheers!!! :D