Set postfix origin to correctly deliver mail for local users

(such as root's cron errors)

roles/mailserver/templates/etc_postfix_main.cf.j2

 # See /usr/share/postfix/main.cf.dist for a commented, more complete version
 # Modified as per http://sealedabstract.com/code/nsa-proof-your-e-mail-in-2-hours/
  
-# Debian specific:  Specifying a file name will cause the first
-# line of that file to be used as the name.  The Debian default
-# is /etc/mailname.
-#myorigin = /etc/mailname
- 
 smtpd_banner = $myhostname ESMTP $mail_name
 biff = no
  
 # information on enabling SSL in the smtp client.
  
 myhostname = {{ mail_server_hostname }}
+myorigin = $mydomain
 alias_maps = hash:/etc/aliases
 alias_database = hash:/etc/aliases
 mydestination = localhost

roles/mailserver/vars/main.yml

     password_hash: TODO@TODO.com
     domain_pk_id: 2
 mail_virtual_aliases:
+  - source: root@TODO.com
+    destination: TODO@TODO.com
+    domain_pk_id: 1
   - source: postmaster@TODO.com
     destination: TODO@TODO.com
     domain_pk_id: 1