iPhone 3G Won't Send Pictures

Hey, I have an iPhone 3G, which now refuses to send pictures. Regular emails work fine, but both trying to send a picture through 'Photos', and trying to copy paste a picture into the email don't work. Stranger, the emails into which a picture is copy pasted do not show up in the 'Sent' folder of my mail. The progress bar when sending it seems to complete, it just never shows up anywhere after that. Any ideas?

I used to be able to send pictures just fine, but it seems to have stopped working since the last time I tried. (It was a while ago, so I don't have anything to attribute it to.)