Hello,
I’m sorry for the inconvenience caused. In photos app you won’t be able to share photos directly to Outlook. As work around you can add your Email account to mail app and make as a primary account and then you can share your pictures through the Mail app.
Use aliases to add email addresses to your account
http://windows.microsoft.com/en-US/windows/outlook/add-alias-account
Hope this information is helpful. Please do let us know if you need further assistance, we’ll be glad to assist you.