Applies To

Call2Teams - Customers


When operating the service between Teams and a PBX platform, two voicemail functions will be active; on the PBX and on the Teams service.

Having two voicemail platforms in operation at the same time can cause problems and careful consideration should be given to the use and configuration of voicemail services on both the PBX and Teams platforms.

Explanation of Behaviour

Typically voicemail is configured to activate after a number of seconds of ringing or if a user is unavailable (either offline or out of service). This applies to both the PBX and Teams voicemail services.

Having voicemail active on both platforms usually means that the voicemail service with the shortest timer will activate and take the call, answering the caller and recording the message.

Customers should plan for several seconds delay between the PBX and Teams services; an incoming call to the Teams user from the PBX may take some time before the Teams service starts the voicemail timer. 

10 seconds is the recommended margin.

It should be noted that if a Teams user is logged out and their voicemail service is enabled then calls will go straight to the user's Teams voicemail. 

Correspondingly, if a PBX voicemail timer is set to a shorter period than the user's Teams voicemail timer then the PBX will answer the call and send the voicemail service.

The main reason that customers use PBX voicemail instead of Teams voicemail is that users may be in a multi-agent or 'hunt group'. 

Incoming calls to multi-agent groups are problematic when Teams users have voicemail enabled, and perhaps logged out. In this case, all calls to the hunt group will be answered by an individual user's Teams voicemail.


In the portal, there is a setting to disable Teams voicemail for all users in an organisation. 

This is provided for customers who prefer to use the PBX voicemail platform.

There is a per-user setting to override the company policy so it is straightforward to disable voicemail for the company but enable it for a few individual users (who may not be in multi-agent groups).

It is recommended for customers operating in multi-agent hunt groups to disable Teams voicemail.

Microsoft Teams has deployed an option to reject phone calls during an MS Teams conference, if this option is active calls will be rejected and sent to the PBX Voicemail, overriding any other option.

Set-CsTeamsCallingPolicy –BusyOnBusyEnabledType configures Busy on Busy. Valid options are:

  • Enabled – new or incoming calls will be rejected with a busy signal
  • Unanswered – the user’s unanswered settings will take effect, such as routing to voicemail or forwarded to another user
  • Disabled – Disables Busy on Busy