Are you trying to send via MMS? (Messaging app)
It's easier to send via GMail or EMail [depending on which you use] -- Make sure you're connected to data. They won't go to space that way.
Of course, the other solution is to mount your phone to your PC as a drive and do it from there.
Remember -- certain email has an attachment size limit. GMail is either 10 or 25 [I forget nowadays]. Which means you're limited to 2 pics to be safe as an attachment (3 can push 10MB, which means 6 pics for 25 I'd limit to). If you're using EMail [non GMail address] then the size is probably 10.