In order to modify user's voicemail greeting in MS Teams there're 2 possible scenarios:
1- The user is working = Very easy and can be configured by himself/herself
2- The user is out of office = The greeting message should be modified by PowerShell.
Scenario 1:
- Click on Teams Settings and go to "Calls" - "Configure Voicemail".
There you can configure a custom message and record one as well.
Scenario 2:
- Connect to Teams Powershell.
- Ensure the user voicemail is enabled and configure the desired message:
Set-CsOnlineVoicemailUserSettings -Identity email address removed for privacy reasons -VoicemailEnabled $true
Set-CsOnlineVoicemailUserSettings -Identity email address removed for privacy reasons -PromptLanguage "en-US"
( Configure the correct prompt language for your user. In this example, it's English from USA ).
- Configure the desired voicemail greeting, ( both cmdlts ), ( Max. 200 Characters :(
Set-CsOnlineVoicemailUserSettings -Identity email address removed for privacy reasons -DefaultGreetingPromptOverwrite "Hello, I'm not available right now. Please let me a meesage and I'll come back to you as soon as possible"
Set-CsOnlineVoicemailUserSettings -Identity email address removed for privacy reasons -DefaultOofGreetingPromptOverwrite "Hello, I'm not available right now. Please let me a meesage and I'll come back to you as soon as possible"
NOTE: This change will take some hours to propagate, ( as usual in Teams ;) ).