Create a property containing the size of an Outlook item's MIME Content
Currently, there is no way to get the size of a Message entity's MIME content before downloading the entire message.
Some libraries such as WindowsAzure.Storage need the size of the written stream to function properly, and without being able to find the size I would need to load the entire object into memory to count the number of bytes. I'm currently working in a low memory environment, so emails with large attachments can cause issues. Ideally, the data is directly streamed instead of buffered.
The Graph service endpoint that gets the MIME content of a Message is not guaranteed to send a Content-Length header depending on the accepted content encodings. Even then, I can't use a HEAD request to get the value of that header before downloading because it returns an HTTP 405 response.
Ideally, there is an endpoint or functionality that would allow me to get the size of the MIME content before it is downloaded.