Used to be that when you shared photos from iPhoto via email, iPhoto would open up Mail app, drop the photos in as attachments, and let you send from there. Nowadays, iPhoto uses an internal email routine that mimics the iOS way of adding photos to email, but many folks just plain don’t like it. If you fall into this camp, and want to disable this iPhoto “functionality,” this tip is for you.
Bypass iPhoto’s Built-In Email Functionality And Use Mail App Again [OS X Tips]

