Emails to my IPad with video attachments even coming from an IPhone result in a message that Safari cannot open the attachment. Do I need to change settings or download something for it to work? Thanks for any ideas.

Tap and hold on the attachment for a list of apps that will open the attachment. If there are none, then you have no apps that can open the attachment. You'll need to go tot he App Store and shop around for one.

Safari has the ability to preview some file types, but not all by any stretch.