I agree--the whole idea of writing oneself into the future seems extremely implausible, especially using something like email.
Much more plausible is the notion that you could modify a "standard median mind" to fit someone's writing. But I suspect that most of the workings of such a creation would be from the standard model than the writings, and also that this is not what people have in mind as far as "writing oneself into the future" goes.
Giulio Prisco made a blog post giving permission to use the data in his Gmail account to reconstruct an uploaded copy of him.
Ben Goertzel copied the post and gave the same permission on his own blog. I made some substantial changes, such as adding a caveat to exclude the possibility of torture worlds (unlikely I know, but can't hurt), and likewise gave permission in my blog. Anders Sandberg comments on the thing.