Launch Outlook from a UWP app with attachments

This demo project demonstrates how to launch Outlook from a UWP application.

Why?

UWP already comes with the possibility to open a mail dialog with the mail app of your choice. However - until this day - attachments will vanish if Outlook is selected as mail client.

But how?

Outlook mails can be saved to *.msg files. Opening an *.msg file will launch the "new mail" window of outlook with subject, body text, recipients etc. already prefilled. Attachments can also be part of an *.msg file.

This demo creates such an *.msg file (using MsgKit) inside of the local cache folder and will launch it from within the UWP app.

That's already all there is to it. 😅

That sounds weird. Isn't there a better solution?

Usually Outlook can be opened using the Microsoft.Office.Interop.Outlook namespace. This, however, is not possible from within a UWP application as it runs inside a sandbox and is not allowed to communicate with other non-app programs.

The only workaround you can find online makes use of the FullTrustProcessLauncher. This solution, however, is a pain to implement and will also result in three different projects - only to launch an Outlook instance.

The solution I present is both simple to implement and will not affect the rest of your project.

How does it look?

The app

The outlook instance