i am going to add a built in function to do this in the near future (probably in september).
BUT:
for most people, all you have to do is start a message to someone in your normal email client, and then DRAG the thumbnail of the image from screenshot captor into the mail message.
The ease and flexibility of this drag+drop is why i haven't bothered to write a special email function.
However, after using stumbleupon toolbar which lets you define some preset names and then send them web urls with 2 clicks, i think something like that should be added to screenshot captor, so that you can maintain a list of friends and quickly send them off screenshots with just a couple of clicks.
