To be able to store the e-mail for your users you have to setup a location that will be used on your servers harddisk. A very common location is ‘/usr/local/virtual‘, but you can put it anywhere you want. Keep in mind that if you use a different location that you need to change this location in the configuration files that we’ll create later on. This is for Tiger only, for the Leopard method look here.

For lots of reasons that go beyond these instructions (security is the largest of them) we need to create a new user called ‘vmail’ on your server, this user account will be used by all programs to access the virtual mail folders. The user has no password or user directory.

sudo niutil -create / /users/vmail
sudo niutil -createprop / /users/vmail uid 102
sudo niutil -createprop / /users/vmail gid 102
sudo niutil -createprop / /users/vmail shell “/usr/bin/false”
sudo niutil -createprop / /users/vmail home “/var/empty”
sudo niutil -createprop / /users/vmail passwd “*”

If you are installing for the first time the directory isn’t there yet. You need to create it and setup the correct permissions. So login to a Terminal session of your server and execute the following commands or use the shell script provided at the bottom of this page.

First create the required directory:

sudo mkdir /usr/local/virtual

Change the owner and group of the directory to be vmail so that the postfix program can read and write into that directory:

sudo chown -R vmail:postfix /usr/local/virtual

and setup the correct permissions
sudo chmod 771 /usr/local/virtual

Next step: Configuring SASL for SMTP authentication