my primary email is "outlook", why can't i send pictures to that email from my android phone?

I've tried sharing photos from my phone to my outlook email without success

What phone?
What version of Android?
What email app?
What is the exact wording of the error message?

Welcome to Android Central! Also, how are you trying to share the photos? Are these photos you've taken with the Camera app, and are trying to share using the Share button in the Gallery app?