There was a time when google toolbar had a search gmail button. I would use it to open gmail using whatever query was inthere. It happened quite often that it found newsletters matching the query. It takes quite a bit of hoarding to accomplish.

Perhaps it is even a better solution than website that vanish eventually. I might one day make a newsletter with links like:

    example.com?re=you@yourwebsite.com&article=1234

Then mail you the requested article. With RE: and the same title they will even be threaded.