cannot send pictures as attachments

Suddenly, I am unable to send even one picture as an attachment - for some strange reason, it is trying to break apart the picture and it ends up sending in pieces? If it even sends at all. Mostly it sits in my outbox. I just tried to send one picture, and it did send, but it came in 16 different emails!  What's going on? I've never had this problem before, and as far as I know I have not changed any settings. I've tried sending old pictures that I've sent before and new ones but the same thing happens.