Internet headers are not returned for mail in sent folder of the user

Start by reproducing the Microsoft Graph request against a message in the user's Sent folder, comparing .select('internetheaders') with fetching and parsing the raw message. Verify whether the limitation is in the TypeScript SDK or the Graph API; done means identifying a supported retrieval path or documenting that no SDK-side fix is possible.

I am building a solution using the Microsoft Graph API where the goal is to retrieve the internet headers of the parent email (the email being replied to). After sending a mail, it appears in my "Sent" folder, and I am trying to reply to it.

I am unable to fetch the internet headers for the parent email, which is critical for propagating important information through my add-in. I tried using both .select('internetheaders') as well as fetching raw message and parsing the MIME content.

I can however fetch the internet headers using the recipient's account. when the mail is in Inbox folder.

This issue is a significant blocker as it prevents the correct propagation of essential security information needed for the add-in to function properly.

I would appreciate any resolution or workaround as soon as possible to address this issue.

Adding the sender to the recipients list is one possible workaround, but I prefer not to use it as it's not a conventional approach.