I do screen capture all the time and just paste the images into my aol webmail. Meaning pasting it into the email and NOT attaching it as a JPEG image or antyhing like that.
Whenever I'm emailing these to people that have aol email or yahoo email, they see the images just fine when they open the email. Whenever the receiver is on gmail, gmail users cannot receive the images.
If the images are attached to the email and not pasted into the email, then everyone gets them just fine (but yeah I prefer just pasting into it).