### Answer Based on the available documentation, the

voicemail_detection_timeout_ms

parameter appears in the API documentation for voice agents [(1) ]() [(2) ]() [(3) ]() , but the Conversation Flow global settings documentation doesn't explicitly mention this specific parameter in the GUI [(4) ]() . The global settings documentation describes voicemail-related settings under "Configure Call Settings" where you can set up voicemail detection and actions when voicemail is detected , but it doesn't specifically list

voicemail_detection_timeout_ms

as a configurable option in the GUI. The API documentation shows that

voicemail_detection_timeout_ms

configures when to stop running voicemail detection, with a minimum value of 5,000 ms (5 s) and maximum of 180,000 ms (3 minutes) , defaulting to 30,000 ms (30 s) [(1) ]() [(2) ]() [(3) ]() . If you need to configure this specific timeout value for a Conversation Flow agent, you may need to use the API to update the agent settings rather than relying on the GUI.

​ To learn more, see the sources I considered: [[1] Get Agent Versions](https://docs.retellai.com/api-references/get-agent-versions) [[2] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[3] Get Voice Agent](https://docs.retellai.com/api-references/get-agent) [[4] Step 1: Configure global settings](https://docs.retellai.com/build/conversation-flow/global-setting) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.