rajjha-msft
commented
2 weeks ago Hey @hazzinator1
This is by design. You can check out the links below
- Upon sending, attached .msg files convert to .eml files - Microsoft Community
- An .eml file that you send as an attachment in Outlook for Mac is not displayed correctly - Microsoft Support
Outlook for Mac does not natively support the .msg file format, which is proprietary to Outlook on Windows. When you attach a .msg file in Outlook for Mac, the application automatically converts it to a .eml file upon sending because it handles .eml files natively. This conversion process is built into the way Outlook for Mac processes attachments, and there isn't a way to disable it within the application.
Your Environment
Expected behavior
We have a bunch of .msg files that we are storing in an online location. When a user wants to attach one of these stored emails to a draft email, we bring that .msg back into their mailbox (in the Deleted section). Once it's there, we call the
Office.context.mailbox.item.addItemAttachmentAsyncmethod with the EWS ID of the rehydrated item.What I would expect to see is these emails being attached without an extension (i.e. a proper Outlook item), and to have them include all of the custom metadata we are putting in them (SentDate, HasAttachments, From, CC etc.). This is how it works for all other instances of this taskpane (Windows PC/OWA and Mac OWA).
Current behavior
These emails are instead getting attached as .eml files without any metadata at all. The customer loses all custom metadata about the email as soon as they attach it as an eml.
Steps to reproduce
Call Office.context.mailbox.item.addItemAttachmentAsync on any item in the user's mailbox and confirm that the item appears as a .eml rather than a .msg or an actual Outlook item.
Context
Makes the experience on desktop outlook poor for our users as they can't share emails correctly