The directions in this tutorial need to be done on the Linux system which is running Postfix. If you are unsure how to create a user account, follow the directions in the article on how to create a new username and password in Linux. This example assumes a new user account named support was created. Before sending the first email to firstname.lastname@example.org, if we use the ls (list) command to list the contents of the /home/support directory, we can see that support does not have a Maildir. Support needs a Maildir to receive new emails. All we have to do is to send at least one email to email@example.com, and Postfix will automatically create the Maildir on the support account. After sending an email to the support account, if we use the list command again to view the contents of the /home/support directory, we will see that support now has a Maildir, and there should also be at least one email in /home/support/Maildir/new/.
root@postfix ~ $ ls /home/support/Maildir root@postfix ~ $ ls /home/support/Maildir/new1448670731.V803I6c004bM330351.example.com