MSGraph provides html content of message as default content when we retrieve message data.
Need to use Prefer: outlook.body-content-type="text" header to get message without html tags which is currently missing in Product.
Wioth the fix note that there will still be a difference between the message contents retrieved from a message using IMAP and graph
In case of processing a MIME message having an alternative part containing PLAIN TEXT PART and HTML TEXT PART with DIFFERENT body(content)
We can retrieve content of BOTH plain text part and html text part and process the corresponding content as per configuration on Service Email .
Although we use the header mentioned above it just REMOVES the html tags in data present in HTML PART and provide message content and there is no way to retrieve data of PLAIN TEXT PART. It is limitation of MSGRAPH
Solution description: This issue is addressed in 8.4.3