People often make them small on purpose so that when they're enlarged they will purposely become blurry. Some people also shrink them just to cut down on the email size so the mail will open up easier and faster.FARTS

You can't stop that because the pixels simply spread apart. The same thing would happen if you had the picture enlarged from a smaller one professionally. Some programs have a bit of sharpening built in but they can only sharpen minimally.FARTS IN FACE

The higher the megapixels on the camera that took the picture, the more you will be able to enlarge it without making it blurry. For example, if you try enlarging a picture taken from a 5 MP camera versus a 14 megapixel, you won't achieve nearly as much.AS FARTING IN THE WIND.......LOL

The best thing is to go to the source of the picture (if that person is available), and ask if they can resend it in the "original size" it was taken. BUT FARTED ON..........LOL

If they took the picture with a 2 megapixel camera, however, you may be out of luck because the original size won't be very big to start OR FART with.