Installation

1. Requirements

• WHMCS 8.0+, PHP 8.0+.
• A SmarterMail 16+ server (Windows) with its REST API v1 enabled.
• A SmarterMail system administrator (sysadmin) account — the module authenticates with it to create and manage domains.

2. Install the module files

Copy the module folder into your WHMCS installation:

modules/servers/smartermail/   →   <whmcs>/modules/servers/smartermail/

No database changes are required — WHMCS discovers the module automatically.

3. Add the SmarterMail server in WHMCS

In WHMCS, go to Configuration → System Settings → Servers and Add New Server:

Field	Value
Name	A label for this SmarterMail server
Hostname	Your SmarterMail server address, e.g. mail.yourserver.com
Module	SmarterMail (Email Hosting)
Port	443 (HTTPS) or 9998 (SmarterMail default HTTP)
Secure	Enabled when using HTTPS
Username	The SmarterMail sysadmin account
Password	That sysadmin account's password

The Hostname you set here is also the default used by the client-area DNS guide for Autodiscover when you leave those product options blank — see Product configuration → Autodiscover.

4. Create the product

In Configuration → System Settings → Products/Services, create or edit a product:

1. Module Settings tab — choose SmarterMail (Email Hosting) and the server (or server group) from step 3.
2. Module Settings — the 23 options that define your offer (billing rates, password policy, which protocols customers may enable, DNS values…). Every option and its implication is documented in Product configuration.
3. Pricing tab — set the recurring price to the price per tranche of GB (see below).

The monthly price you set is not a flat price — it is multiplied by the number of disk-usage tranches the customer consumes. Example: a price of $6.00 with GB per billing tranche = 10 bills a customer using 21 GB at 3 × $6.00 = $18.00. See Billing model.

5. Schedule the usage cron

Disk-usage billing relies on WHMCS calling the module's UsageUpdate function, which queries the SmarterMail API for each domain's real disk usage and writes it to tblhosting.diskusage.

• Make sure the WHMCS system cron is configured (Utilities → System → System Cleanup / the documented WHMCS cron).
• Run it at least daily so invoices reflect current usage.

Without the cron, diskusage stays at its last known value and invoices may bill stale usage.

6. Verify

• Place a test order (or use Create on an existing pending service). The domain should appear in SmarterMail with a hidden admin account.
• Open the service in the WHMCS client area — you should see the dashboard, the mailbox manager and the DNS guide.

If Create fails, the most common causes are: wrong sysadmin credentials, the REST API disabled on SmarterMail, or a firewall blocking the API port.