Currently, Sharing links and files from the Inbox is not supported for Outlook-based users. To learn more about the Mixmax integration with Outlook, check out How to use Outlook with Mixmax.
With Mixmax, you can easily share an email with someone when forwarding isn’t an option and copy and pasting is too clunky. When you click the Share button (see the screenshot below), it creates a unique share URL (e.g., https://mail.mixmax.com/m/5m3VxNmUJ75NZdxRa). The ID on the URL is random, so it's nearly impossible to guess.
Each time you share a link or file using Mixmax - you can choose who can see it and how long the link is active. You now have the following options:
Anyone with the link can view
Anyone in my domain can view
Only I can view
The default for shared links is Anyone at my Domain.
Expiration Dates
You can control who can see a shared link and the length of time it can be viewed. When you create a link in Gmail, you can set an expiration date immediately.