When you send an SMS via an enabled toll-free # using high volume SMS, what happens when the recipient tries to call or send a reply SMS to the number the SMS was sent to them from?
If the recipient calls the number, the user extension who is assigned with the TF number will receive a voice call if he/she login a RingCentral softphone app or RC app etc. If the recipient reply with a text message, those app will not be able to receive the replied text message but the message is stored in the user A2P message store. You can implement a push notification to receive the reply text message or you can read the A2P message store to read the message.
In addition to @Phong's answer the following reference says:
"Customers can also send text messages to toll-free numbers, so long as those numbers are “text enabled,” and businesses can send texts in response.”
Using the RingCentral Phone for Desktop, you can dial or receive test calls, send and receive test SMS or Fax messages in your sandbox environment.
Download RingCentral Phone for Desktop:
Tip: switch to the "sandbox mode" before logging in the app:
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