Why won't my e-mail attachment get sent?
Answer: The most likely reason you can't send the file is because it's larger than the disk quota your ISP allows you to have. The disk quota is how much space your e-mail account is allowed to use up. When you send a file, it must be under that amount or it won't get sent.
If you are attempting to send just a picture, and it won't go through, that means the image file is probably very high-resolution and un-compressed. Most images are not more than a couple hundred Kilobytes at the most (1024 KB in 1 MB). If you convert it to JPEG (.JPG) format, it should be easily small enough to send.
If you don't have a image-editing program that can do this, you can most likely find one at Download.com. Just enter "JPEG" or "image-converter" in the search box and you should find a good program that you can download and use to compress your image files.