I am looking for recommendations on the best Rails plugins and gems for parsing email and inserting it into the database, similar to the way Highrise and Basecamp (among others) work.
Described here http://wiki.rubyonrails.org/rails/pages/HowToReceiveEmailsWithActionMailer
Are there any that people recommend, currently?
Scott,
Perhaps some more information would be better? What exactly are you needing to do with the e-mails? Parse them?
Natural language parsing is an entire topic all unto itself, of course. But I doubt anyone's needs would go so deep as to need to parse natural language for something like this.
Fetching/receiving the e-mail is simple enough, as you've provided in a link yourself. I personally would go with the route of the example under "Receiving with Net::POP3/IMAP", since I detest setting up any sorts of mail servers on a unix box. Imho, it'd be the absolute easiest to set up a google mail account (http://www.google.com/apps/intl/en/business/details.html) and connect to that using a cron'd script (NOT using script/runner, heh).
Once you do that, setting up a parser to interpret commands via subject line and to import messages in the body would be trivial. Which is likely why there aren't any plugins built for something like this yet.
Sorry if this wasn't exactly the answer you were looking for, but it seems pretty simple to just roll your own.
I'd suggest looking at astrotrain. I haven't used it myself, but I gather it's what the entp guys are using for their apps.