We have a message-only extension set up to receive after hour calls. It is configured to send a notification by both Email and SMS whenever a voicemail is left. This works fine most of the time.

Occasionally we get only the email, but not the SMS notification, and it seems to be only when the voicemail is empty. Is this behavior by design?

This is not a big problem since it only seems to happen when the voicemail is empty, but we wanted to make sure that's the only time it fails to send the SMS message. I tried to reproduce the behavior by calling and hanging up without leaving a voicemail but it always send both notifications in my testing.

We are a very small company in the US with less than 15 extensions and a very simple setup.