We recently set a first message spoken first by the assistant and since then, we are experiencing issues with voicemail detection. it is very strange what is happening, all calls end up being flagged as voicemail and you cannot hear any recording as well, while the assistant is speaking. Also some calls are clearly not voicemail. Can you help us with checking this please? call ids: 85a0129a-ff37-4af9-bea4-7273161242e4 18158e4f-137d-43a1-868d-d5343a37e6c5 ee63de66-7dd4-460a-b6ff-0c4f771f1715 clearly not voicemaiil: a9fda214-4f1b-47b5-b81b-b7e6092f524f Also generally voicemail since not reliable, I am having issues with it sometimes the assistant just continue speaking and leaves messages. I did try OpenAI, Twilio and Google detection. Thanks in advance, appreciate you support here 🙏

Hi there! 👋 I understand you're having issues with voicemail detection after setting a first message for your assistant. While I can't directly check the specific call IDs you've provided, I can definitely help with the general voicemail detection issues you're experiencing after setting a first message. Based on the information I found, there's a known issue where setting a first message spoken by the assistant can interfere with voicemail detection. According to [user reports](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1334001638876250233), after setting a first message, "all calls end up being flagged as voicemail and you cannot hear any recording as well, while the assistant is speaking," which matches exactly what you're experiencing. Here's why this happens and how to fix it: ### Why First Messages Affect Voicemail Detection The first message in Vapi is "guaranteed to be spoken and cannot be interrupted," which can interfere with the voicemail detection process. When your assistant starts speaking immediately, it may not give the system enough time to properly detect if it's a voicemail. ### Configuration Recommendations 1. **Adjust First Message Mode**: Set

firstMessageMode

to

assistant-waits-for-user

to prevent your assistant from speaking before detection completes. This "can give you smoother call handling—your assistant won't barge in if someone unexpectedly picks up late" according to [Vapi documentation](https://docs.vapi.ai/phone-calling/voice-mail-detection). 2. **Add Delay Before Speaking**: Increase

startSpeakingPlan.waitSeconds

to give the detection more time before your assistant speaks. 3. **Optimize Twilio Detection Settings**: ```json "voicemailDetection": { "provider": "twilio", "enabled": true, "machineDetectionTimeout": 30, "machineDetectionSpeechThreshold": 2400, "machineDetectionSpeechEndThreshold": 1200, "machineDetectionSilenceTimeout": 5000,

Can you read this guide this should help.

Thanks for getting back to me, somehow I was aware of these rules, but we wanted to try making our first contact with the customer faster. Although I am still confused why the recording doesn't contain the voicemail audio, only the assistant speech. In any case right now we are using first-message-mode = assistant-waits-for-user

if you still need assistance with this, feel free to open a new request