Uploading a large attachment using Microsoft Graph
问题 I am trying to upload a large (> 4mb) attachment to an existing message in Office 365. I am following these instructions: https://docs.microsoft.com/en-us/graph/outlook-large-attachments?tabs=http I have successfully created the upload session, and obtained a uploadUrl value that looks legitimate, it roughly matches the example in the documentation. Then I start my PUT to this url, for the first byte range that I've selected. I'm sure I'm setting the Content-Type, Content-Length and Contact