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Based on my testing, I reproduce this issue. In fact, the voting feature is a feature that Microsoft Forms integrated into the Outlook client, and cannot be set up in the Outlook client, which is the expected behavior.
To limit voting to one time, I recommend that you set up a poll in your Microsoft Forms and then email the link to the user. Select the One response per person option in the form to prevent multiple votes. More information, see: Adjust your form or quiz settings in Microsoft Forms.
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