I used to be able to reduce photo attachment when sending mail. I think the word i age was under cc and bcc and once tapped, you had 3choices, cant see it now. Can it be to do with update to io7
The feature is still there. Here's how it works. Select a photo from the camera roll and tap on the symbol at the lower left of the screen. . Next, tap the mail icon. Tap the image size. Select from any of the offered image sizes. Email your photo.
Hold in mind that the sizing option in Mail only shows up if your attached photo(s) are over a certain size to begin with. I think it was about 500KB last time I checked. That was iOS 6. I have not checked to see if the behavior and size limit/trigger have changed in iOS 7.
This also works the same way if you open a new message and press-hold to import an image, rather than starting in Photos. This post handcrafted from 100 percent post-consumer recycled electrons.