Why can't I get pictures on iMessage?

Me and my friend are sitting here and he is trying to send me a picture. When he sends it on his phone it will show that it's delivered but I haven't actually got it. I'm using an iphone 5 and him an iphone 4.

IMessages send thru Wi-Fi. Pictures aka MMS can only send thru data, like 4G, 3G, LTE

  • Why won't my iPhone 4 send pictures on iMessage? It's a new iPhone and it won't send pictures for some reason. It said "not delivered when j try to send pictures". Can someone do a step by step process with me? Like send me everything I have to do?
  • Why is iMessage taking so long to send pictures? Just recently my iPhone 5 (AT&T) has started to take insanely long amounts of time to send pictures(and sometimes just texts) through iMessage. Whether on 4G LTE or on Wi-Fi (both with full bars) it takes ridiculously long, or just won't send. This only started less than a week ago but everything i tried has been unsuccessful. Turning iMessage off, turning cellular data off… I'm not sure what else to try. And a new billing cycle just began so i'm not out of data yet.
  • Why can't I send pictures on my iPhone when it's NOT on iMessage? I have an iPhone 4 and it sends text messages perfectly fine. It sends pictures only on iMessage! Why won't it let me send pictures when it's just a regular text message (aka when the conversation boxes are green). Not all of my friends have iPhones so I can't send pics through iMessage to them, why won't my pictures go through? It will just say "did not send" or something like that.
  • IPhone can't send iMessage to iPod touch user with iMessage? At random times, whenever I try to iMessage my friend who has just a iPod Touch, where you type in the message will say "Text Message" instead of "iMessage." is there a way to fix this so it will always send as a iMessage instead of Text?