In conversation flow - I am trying to transfer to an end user (external phone number). The goal is a warm transfer if they answer, but leave a voicemail if they don't. I have tried with set both with Transfer only if a human answers. with a 80s detection. And also with that turned off. - I also have the Global Call Settings set to 'Leave a message if reaching voicemail' and moved the ring duration to over 1min. With all of these - no matter what, the Voice agent takes the call back at around 16 seconds, and says the caller wasn't reachable. And doesn't leave a message. Does anyone have an idea how to get the agent to let the ring more than 16 seconds and leave a voicemail?

Hey @Alex911 This is expected behavior with Retell right now. During a warm transfer, there is a built-in answer detection window, and if no human or voicemail is detected within that time, the transfer is marked as failed and the agent takes the call back. This happens even if you increase the global ring duration. The leave voicemail setting only works when voicemail is actually detected, not when the transfer times out. To give voicemail a chance, you need to increase the agent-level ring and detection timeout, not just the global settings. If the call keeps returning around 16 seconds, it means detection is ending early and at the moment Retell does not support forcing longer ringing during warm transfers.

I did increase on global, and the transfer node, and I also tried cold transfers (which is not what I want, but just for testing), which also had the same behavior of picking the call back up around 16 seconds. So essentially, there is no workaround to extending the ring time before retell agent picks up? Any thoughts to support this feature?

You can submit this as a feature request in the #1209348383496732682 page, and our team will review it and work on improving the experience.