Is it possible to use Office Javascript API to set subject of selected email in Outlook?

Question

With VSTO add-in I can change the subject of the selected email. To prepend something like a ticket number, for instance. But this does not seem possible with the Javascript API. It looks like I have to be in compose mode for this, which is not what I want.

Does Office.context.mailbox.item.subject.setAsync only work in compose mode? Or can I somehow make it work for the selected item/email? Or is there any other way to change the subject of the selected email?

Answer 1

Office.context.mailbox.item.subject.setAsync only works in compose mode. You can set properties on the email using custom properties though if that works for your scenario: https://learn.microsoft.com/javascript/api/outlook/office.customproperties?view=outlook-js-preview