I've also encountered this problem here. May I ask if you have found a solution so far?

Hi ​@owen.-l,

Could you please submit a Support ticket so our team can take a closer look at this issue? To help them troubleshoot as quickly as possible, it would be super helpful if you could provide:

• The RingCentral phone number that isn’t receiving messages

• The full phone numbers of the people getting the error

• Their mobile carriers (e.g., Verizon, T-Mobile, AT&T)

• The exact date and time when the messages failed

Sharing these details upfront will help our team trace the messages and figure out what’s causing the routing issue. Thank you!

Yes, I have submitted the case tracking number query and provided some sample information. It was found that when the T-Mobile numbers were sent to our RC, "Sorry, this service is not available" would pop up. The query reply given by the case number was a problem with the operator on the T-Mobile side. However, I'm not sure if this conclusion is correct.

Thanks for sharing this! I’ll take a look to see if there are any similar cases so we can be sure.