I am trying to find some management system for project I am starting and it has already many e-mails. We want to start full free support by e-mails. It means some ticket system for e-mails like I saw in other companies which somehow order emails to tickets and automatically answers them with message that it will be answered in a few days or so.
I saw in many projects emails with subjects like Ticket #23986522
or [Ticket#2010070610102874] RapidShare
for rapidshare support.
So again my question what is the best/reliable managements system for handling many e-mails for free or at least for minimum price (open source in best case)? I have my own domain and e-mails. Thank you