I believe everyone has used WHMCS. Foreign host providers basically use WHMCS to manage the sales of host domain names, and WHMCS authorization is not expensive. It can be used with various panels such as VPS, independent servers, domain names, and virtual hosts. Easy to integrate, as long as you want to enter the IDC industry, WHMCS is essential.
WHMCS is a very powerful financial management system. Since I used WHMCS to connect SolusVM when building its cloud host, I found that I encountered many problems when using WHMCS. The first problem is that WHMCS switches to SMTP for sending letters. By default, you can use PHP of WHMCS to send letters, but most of the letters sent are thrown into the trash by major mail providers.
