Some of our users are getting 10 second long silent voicemails. The caller calls a backdoor number which then rings their extension and if not picked up the voicemail message starts. If the caller hangs up before the beep to leave a voicemail, an empty message of 10 seconds is left on their phone. Is there a way to have it leave a message only if a message was intended, i.e. if something was left after the beep? Also, very short messages like messages of 1 second (after the beep) are getting dropped. Ideally anything left after the beep no matter how short should be saved as a message.