Is there a Casetracking system in Drupal that does any automatic processing of email support requests?

Maybe the answer to this is out there, but I did some searching for a while and I can't find out if this exists:

I really need a Casetracker, trouble ticketing system, helpdesk, or whatever you want to call it that has some automated processes: I want it to automatically create trouble tickets or cases or something like that when email is sent to a specific address.

Ideally I'd like it do what most ticketing software like this does -- receive case updates from the customer via email (to the reply-to address) and add a posting to the case for it -- and also ideally send out email to the customer when we update the case.

There are a number of external solutions for this -- in fact, web- based casetracking services seems to be the big craze now, but I really need this integrated as part of our Drupal site. It seems like someone would have done this by now.

Does anyone know of an option for this in Drupal, or have any suggestions as to how to put this together?

Thanks in advance!

P.S. Here's an example of a system online that seems good; I'd love to have even some of these features in our drupal site:

http://www.fogcreek.com/FogBugz/LearnMore.html?section=CustomerEmail