List the attachments on an Outlook email message and download their contents, handling both small inline-encoded attachments and large (up to 150 MB) attachments via the raw $value endpoint.

Documented steps

1. Acquire a token with delegated Mail.Read (least privileged) to list/get attachments, or Mail.ReadWrite to add attachments.
2. List attachments: GET https://graph.microsoft.com/v1.0/me/messages/{message-id}/attachments — returns a collection of attachment objects (fileAttachment, itemAttachment, or referenceAttachment), each with id, name, contentType, size, isInline, and for fileAttachment, contentBytes (base64-encoded).
3. Get a single attachment's metadata: GET /me/messages/{message-id}/attachments/{attachment-id}.
4. Download raw bytes: GET /me/messages/{message-id}/attachments/{attachment-id}/$value — returns the raw file content; for item attachments (contact/event/message) it returns vCard/iCal/MIME format respectively.
5. Check the attachment's @odata.type first: calling $value on a referenceAttachment (e.g. a OneDrive link attachment) returns HTTP 405, since there is no raw content.
6. To add a small attachment (<3 MB): POST /me/messages/{id}/attachments with body {"@odata.type": "#microsoft.graph.fileAttachment", "name": "...", "contentBytes": "<base64>"} (requires Mail.ReadWrite).
7. For attachments between 3 MB and 150 MB, POST /me/messages/{id}/attachments/createUploadSession with an AttachmentItem body ({attachmentType: 'file', name, size}), then iteratively PUT byte ranges to the returned uploadUrl; the final PUT response header contains the new attachment's ID.
8. Docs: https://learn.microsoft.com/en-us/graph/api/message-list-attachments ; https://learn.microsoft.com/en-us/graph/api/attachment-get ; https://learn.microsoft.com/en-us/graph/api/message-post-attachments ; https://learn.microsoft.com/en-us/graph/outlook-large-attachments