How to retrieve Internet (Message) Headers via Office 365 REST API?

Question

I am currently working on a project in python to interface with the Office365 REST API, but I need to retrieve (all of) the Internet Message Headers for specific emails.

I've used the $metadata file to research the exposed properties and I don't see an obvious method to access this information.

I know that you can access the headers in OWA using "Message Details" so I would think that the information is web-accessible (even if it is not through the REST API).

Any help would be appreciated.

Answer 1

This is now possible in 2019.

In your $select parameter, you can now specify InternetMessageHeaders to get all the MIME message headers.

Tested using this Postman request:

https://gist.github.com/elliotfiske/ccf81266be6ead10823a53c094749234

Be sure to substitute in your own Bearer auth token.