Hi Joel,
You should do the screen configuration. From the screen configuration, you can enable the attachment view.
If you are administrator, then you can publish changes too everyone. To do the screen configuration, you should do the following steps:
1. Open the Microsoft Silverlight@ mode from adapt link\tab on right corner top of your the screen
2. Go to Adaptation mode from adapt link\tab on right corner top of your the screen
3. Open the Email activity
4. Open the screen configuration mode( edit screen ) from adapt link\tab on right corner top of your the screen
5. Select the Attachment ( make it checked ) for tab
6. Save and publish your changes for everyone.
Hope this will help to configure the attachment view for email activity..