best response confirmed by ThereseSolimeno (Microsoft)
Solution

Hi @am95

Have opened a uservoice for you here

https://microsoftteams.uservoice.com/forums/555103-public/suggestions/43725420-voicemail-full-abilit...

Think it's a good idea to have an option so vote to push up the agenda (uservoice is still being used a while). An alternate option is to have users use call answering option to play the greeting and the end the call preventing leaving a voicemail

Hope that answers your question

Best, Chris

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