add a stamp on Email headers when using office.js Add in on Outlook

Question

I am trying to replicate this below behavior on my Office add in for outlook, but I am not able to find the right API to use, can someone help with that?

Does Office.context.mailbox.item contains any of the functions needed to do so?

I know that I will need to add the stamp using the customProperties as it is related to the email

but how can I add the Stamp?

Answer 1

For just stamping a message in UI, you can try to use outlook categories. Please check Get and set categories for available categories API. For adding the stamp to the message you can either use custom properties or internet headers