An Account is the basic service unit: every user served with a CommuniGate Pro Server should have an Account on that Server.
Each Account is protected with a password, so only the Account owner (and, optionally, System and Domain Administrators) can have access to Account data.
The postmaster Account is automatically created in the Main Domain. The Master (unlimited) access right is granted to that Account.
The pbx Account is automatically created in the Main Domain. See the PBX section for more details.