sending a pic in a text


I'm trying to send a pic in a text..and i get a Not Delivered..I have a iPhone 5 and the person I'm trying to send a pic to has a different
phone..So what am i not doing..or not doing right ?..Thanks for any help..
Not delivered could mean a number of reasons. First that your phone number was blocked by that person, or that person does not get pictures/images in text messages, or that person doesn’t get text, or the image is way to large to send as text, or ..... any number of reasons.

The question is have you been able to send pictures to other people before with this phone? Have you sent messages to this person before?
Thanks Cheryl….Ive sent pic and text to this person… But it could be the pic is too big..ill try sending a pic I've sent before to see if that goes thru..Thanks Again