The MiMSMS (eSMS) SMS Notification Plugin offers many features which are beneficial to many companies who use WHMCS as their billing system
The best place to start if you need help with a specific product is to contact the developer. All WHMCS Marketplace developers have both a website and support URL listed.
v1.0 Released Jan 01, 2019 Latest Version First release
MSG91 WHMCS SMS plugin gives you the power and flexibility to stay connected with your customers by sending them an SMS and OTP's for 2FA at the crucial steps that matters the most.
Transactional email support for Sendgrid, Mailgun, Postmark, Sendinblue, Mailjet, Sparkpost, Mandrill and AmazonSES
More Advanced SMS System (Two-Factor Authentication)
Netgsm Sms addon provides you sending customized bulk sms and creating sms templates.
Professional business e-mail for your users