The Miva merchant option is avaiable under advanced features at the time your setting up a domain. If you donot add it at this time you can go back and add it later.
Goto Sites in the left nav bar
Click on the pencil next to the domain to add the service to.
Click advanced at the bottom of the main page.
Select miva merchant than save.
Miva Merchant licenses are available at csesupport.com
Log into the Appliance admin user interface and select "Services" from the left nav bar. Find sendmail in the list of services and click the pencil to the right of it. Click on "Edit Configuration" on the main page. You can enter the maximum email message size allowed through your server and add domain names or IPs to your list of sites allowed to sendmail through your server.
Log into the Appliance or Site admin user interface and select "Services" from the left nav bar. Find sendmail in the list of services and click the pencil to the right of it. In the top menu you will see a link called "Spam Filters" click on it and than select "Add a Spam Filter" than follow posted instructions.
Log into your Administration web GUI and select "Sites" from the left nav bar. At the top of the screen you will see a query box that says add, this is where you will select the type of domain you wish to setup on your private server. There are two choices, IP and named based. Depending on your account type you may not have access to setup both types of accounts.
RSE - IP based only
WebmasterSE - Name based only except for first domain.
WSE - IP and named based.
After you click on add follow the on screen instructions.
You actually would not directly add a pop account. Log into your Appliance web GUI and select "Sites" in the left nav bar. You will then see a list of the domains on your server. Find the domain you would like to add users to and click on the pencil to the right of it. Click on advanced on the bottom of the screen and you will see "Max Users:" listed, increase this to whatever you like and hit Add/Save on the bottom. This will allow your client to add additional user accounts.
You currently cannot control if the domain uses the accounts you unlock for Telnet/FTP/POP this will be determined by your client when he sets them up in the Siteadmin user interface.