VICIdial AMD: Hang Up the Machine or Leave a Message

When answering machine detection (AMD (answering machine detection)) decides a call is a machine, you have a fork in the road: hang up and move on, or play a recorded message before you do. Both are valid. The right answer depends on your goals, your compliance posture, and whether a message actually helps your campaign. This post compares the two outcomes and shows the fields behind each.

The hang-up path

Hanging up is the default behavior. With AMD send to Action set to N, the moment detection labels the call a machine, the system ends it. No audio plays and no agent is tied up. The benefit is speed and simplicity: you only ever spend agent time on live humans, and there is nothing to record or maintain. The lead still gets a call status (Status (lead status)) written, so you can recycle or report on it later.

This path suits campaigns where a machine answer has no value, or where leaving messages would raise compliance questions you would rather avoid.

The leave-a-message path

The other option drops a recorded message onto the machine, a voicemail drop (Voicemail drop). To do it you enable the AMD send to vm exten field and put a prompt filename into the Answering Machine Message field. The prompt lives in your audio store as GSM 8k 8-bit mono or WAV PCM 8k 16-bit mono. Recording the message twice back to back is a reliable trick, because if a machine clips the first few seconds the customer still hears it through once.

You can cap how often a message plays to one lead in a day with the Voicemail Message Daily Limit, after which calls are hung up instead. That keeps you from hammering the same voicemail box repeatedly. There are also more advanced touches available, such as wildcards that swap in a different message based on a lead field, but the core decision is still message or no message.

What drives both paths

Both outcomes hang off the same control: AMD send to Action. Left at its default of N, every detected machine is hung up. Switch it on and the call is sent onward to the message path instead. So the choice is not two separate features but one field that flips the behavior, with the message option needing the prompt and extension in place before it does anything useful.

A practical middle ground exists too. You can keep hanging up most machines but reserve messages for a specific list or campaign where a voicemail genuinely helps, since the message fields are set per campaign. That lets your high-value lists leave a recording while your bulk lists stay lean and fast.

Choosing your outcome

flowchart TD
  A[Machine detected] --> B{Want a message left}
  B -->|No| C[AMD send to Action N]
  C --> D[Hang up immediately]
  B -->|Yes| E[AMD send to vm exten Y]
  E --> F[Answering Machine Message prompt]
  F --> G{Daily limit reached}
  G -->|No| H[Play message]
  G -->|Yes| I[Hang up]

Trade-offs at a glance

• Hang up: zero airtime cost, no audio to maintain, fewer compliance questions.
• Leave a message: keeps your brand in front of the lead, but uses line time and needs a clean recording.
• Either way, detection only runs on auto-dial methods such as predictive dialing (Predictive dialing).

For the full picture of how detected calls move through the system, read our AMD and CPD complete guide, and for the single field that triggers both paths see the AMD send to Action setting.

Both paths assume the message extension and audio store are wired and ready, which is exactly what a managed cluster gives you on day one. See VICIfast pricing to skip the setup and choose your outcome straight away.