Image src attribute in email body using microsoft graph about aspnet-snippets-sample

[jasonjoh]

I know this is an old issue, but I wanted to provide an answer anyway.

That format in the src attribute indicates that the image is attached to the message. To render it, you must get the attachment that has that CID stamped on it and insert it in the appropriate place. The CID will be in the contentId property on the attachment.

See https://docs.microsoft.com/graph/api/resources/fileattachment?view=graph-rest-1.0