I think that you could email scanned autographs. They are after all handwritten and I suppose they have the same value. Of course they aren't as good as real live written autographs but if you really want one the are not that bad.
While you can email autographs, no collector would characterize them as "real. " To be real, an autograph must be handwritten on a tangible material such as paper, a book, or a sports ball. Authentication is important, for example, being at the sporting event and getting an athlete to sign a program.
Emailing an autograph will not be authentic. Since the autograph is scanned into the computer, and emailed, it is obviously not going to be the real thing when you print it out. While it may look like it, the autographee did not sign the printed paper.