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When your AI agent makes outbound calls, two obstacles can derail efficiency at scale: calls that land on voicemail instead of a live person, and calls that hit an automated IVR menu requiring button presses before reaching the right department. VoiceInfra handles both automatically. Voicemail detection identifies answering machines the moment they answer and responds according to your configured preference. IVR auto-navigation reads menu prompts and presses the correct keys without any manual input. Together, these features keep your outbound campaigns running cleanly and your agents spending time on real conversations.

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Voicemail detection

On every outbound call, VoiceInfra listens to the opening audio and identifies whether a human or an answering machine has picked up. Detection happens within seconds of connection — before your agent has said a word. When voicemail is detected, you choose what happens next:

Hang up silently

End the call immediately. No message is left. The call is logged as Voicemail in your dashboard. Best for campaigns that only want to track live-answer rates.

Leave a pre-written message

Enable Smart Voicemail Handling and configure a custom message. Your agent reads the message after the beep, so every voicemail gets a professional, on-brand follow-up.

Custom behaviour

Use your agent’s system prompt to define conditional logic — for example, leave a message only for certain contact types, or vary the message based on campaign variables.
Why it matters for campaigns: voicemail detection prevents your campaign from running up minutes on unanswered calls. Only connected time is billed, and detecting voicemail early minimises that window. In batch campaigns, every voicemail call is logged with a Voicemail status so you can measure true live-answer rates and adjust your scheduling accordingly.

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IVR auto-navigation

Many businesses — suppliers, healthcare providers, enterprise partners — answer inbound calls with an automated IVR: “Press 1 for Sales, press 2 for Accounts.” Without IVR navigation, your AI agent would stall at that menu indefinitely. With IVR Detection enabled, your agent:
  1. Listens for keypad prompts during the outbound call
  2. Reads your configured navigation instructions
  3. Sends the correct DTMF (keypad) tones automatically
  4. Continues through multi-level menus until it reaches the right person or department
Example scenario: your AI agent is calling a supplier to check on a purchase order. The supplier’s IVR plays “Press 1 for Sales, press 2 for Accounts Payable.” You’ve configured your agent to press 2 for Accounts. The agent navigates the menu automatically and reaches the right team — with no human intervention.
IVR auto-navigation applies to outbound calls only. For inbound callers navigating your own menu, use the Keypad Routing feature in call transfer settings.

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Configuring voicemail detection

1

Open the Functions tab

In your agent configuration, navigate to the Functions tab.
2

Enable Voicemail Detection

Toggle Voicemail Detection on. This activates detection for all outbound calls made by that agent.
3

Choose your voicemail action

Select what happens when voicemail is detected:
  • Hang up immediately — ends the call with no message left
  • Smart Voicemail Handling — enables message delivery; enter your custom voicemail message text in the field that appears
4

Save and test

Save your configuration. Run a test call to a number you know will hit voicemail to verify the agent behaves as expected before launching a campaign.

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Configuring IVR navigation

1

Enable IVR Detection

In the Functions tab of your agent configuration, toggle IVR Detection on.
2

Add navigation instructions to your system prompt

Open your agent’s system prompt and add step-by-step IVR navigation instructions. Be explicit about the sequence — for example:
When you reach the main menu, press 2 for Accounts Payable.
If a sub-menu appears asking for department, press 1 for billing queries.
The agent follows these instructions precisely, so match them to the current menu options of the number you’re calling.
3

Test navigation

Run a test outbound call to verify the agent navigates the menu correctly. If a menu option changes, update your system prompt instructions.

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Use cases

Outbound sales campaigns

Detect voicemail → leave a personalised message referencing the contact’s name and company → log the call as Voicemail. Your live-call metrics stay clean and every unreached contact still gets a professional follow-up.

B2B calling and supplier outreach

Navigate company IVRs automatically to reach the right department — accounts payable, procurement, technical support — without a human operator having to sit through the menu.

Follow-up campaigns (live-only)

Disable Smart Voicemail Handling and configure the agent to hang up on voicemail. Your dashboard shows only live-answer outcomes, making it easy to build a retry list of unanswered contacts.

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Frequently asked questions

Yes. Voicemail detection works across all countries supported by VoiceInfra. The AI analyses audio patterns rather than relying on country-specific signalling, so it functions reliably regardless of carrier or region.
Yes. Each agent has its own voicemail message configured in the Functions tab. You can use different messages for different campaigns, contact types, or products simply by using separate agents or updating the message between campaigns.
Update the navigation instructions in your agent’s system prompt. The agent follows your instructions on every call, so keeping them accurate ensures reliable navigation. Always re-test after making changes.
Only connected time is billed. Voicemail detection identifies answering machines quickly — typically within seconds of connection — which minimises the billable duration for unanswered calls. There is no additional fee for the detection feature itself.
VoiceInfra uses AI-based audio analysis to distinguish human greetings from automated answering machines. The detection is highly accurate and designed to minimise false positives (treating a live human as voicemail) which could cause a real caller to be disconnected.
Yes. As long as you provide clear, sequential instructions in your system prompt, your agent can navigate through multiple levels of nested IVR menus before reaching the target person or department.