I have developed a solution that can download selected memo in mime format and process it (solution works as an addin in outlook web/client).

I fetch data from emails like this (with graph or api v2.0)

https://outlook.office365.com/api/v2.0/me/messages/{uuid}/$value

https://graph.microsoft.com/v1.0/me/messages/${uuid}/$value

However when I try to get an email from shared mailbox it fails

{
    "error": {
        "code": "ErrorInvalidMailboxItemId",
        "message": "Item '*******************GAAAAAABWtYncIxJ9Tr9kkgiMGaNGBwDLj7SD7a9lRI0-8mlYFHqoAAAAAAEMAADPq6uIKft4RaiCqD-1XViEAALJ75k9AAA=' doesn't belong to the targeted mailbox 'a8****67-****-****-****-c7d8****5b2c'.",
        "innerError": {
            "date": "2022-03-31T09:21:08",
            "request-id": "189dc3f3-4813-4974-a873-bda9cb799636",
            "client-request-id": "189dc3f3-4813-4974-a873-bda9cb799636"
        }
    }
}

My account has access to shared mailbox in UI (client/web app) however via API it's not working.

Is there a proper way to solve my need?