In this documentation, we can check how to manage mass mail tool in WHMCS. Mass mail tool allows you to send emails to selective groups of your clients. The type of email you choose to send will determine what merge fields you can include within it.
1) Login to WHMCS admin panel.
2) Go to ‘clients’.
3) Click the option ‘Mass Mail Tool’.
4) Select the email type.
5) Each type has different options.
General
Product/Service
Addon
Domain
6) Click on the button ‘Compose Message’.
7) Enter the details and click the button ‘Send Message’.
That is how we can manage mass mail tool in WHMCS.
If you need any further help please reach our support department.