Hello @Andy Green,
Thank you for reaching Microsoft!
The Outlook REST API version 2.0 has been deprecated. As of November 2022, the v2.0 Outlook REST endpoint has been fully decommissioned. It is recommended to migrate existing applications to use Microsoft Graph. Please refer to the following link to use the Outlook Mail REST API in Microsoft Graph: https://learn.microsoft.com/en-us/graph/api/resources/mail-api-overview?view=graph-rest-1.0
Documentation reference: https://learn.microsoft.com/en-us/previous-versions/office/office-365-api/api/version-2.0/use-outlook-rest-api
Hope this helps.
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