Photo Attachments in Mail

OK... So recently, whenever I go to add a picture or multiple pictures to an email attachment, it ends up doubling the size of the picture or pictures. For example, if I try to send a 2 MB image to someone, I get the following options:

Actual Size: 4 MB - should be 2 MB!

Large: 1.5 MB

Medium: 251 KB

Small: 64 KB

The ORIGINAL 8 megapixel image is really only 2 MB to begin with ( I have verified this via several third-party apps that show all the metadata in a photo) as well as on several computers. Basically, Apple is doubling the size of my photo on my end, but the person who receives it gets the correct 2 MB image. So it should NEVER appear to be 4 MB on my end, because the image is simply not 4 MB- it's only 2. This is driving me nuts! Any suggestions??