I just spoke with an Amazon representative, and she was emphatic that the number of customer complaints/requests they receive about this issue will impact how eager they are to make a change. So e-mail them and add your voice; even ten or twenty more might be enough. Try something like this:
TO:
kindle-feedback@amazon.com.
Dear Amazon,
I would very much like to have Calibre news, KindleFeeder News Feeds, or .mobi periodicals e-mailed to my @kindle.com address work as fully-functional periodical files on the Kindle Touch, so that I can use the
"Sections & Articles" navigation page. Can you enable this? Right now, it seems that the e-mails are converted or otherwise set to "e-book" form, so that I cannot use the "Sections & Articles" navigation page. This is important functionality and has a big impact on my reading experience with the Kindle Touch.