This is SupportPress.

Brief installation instructions:

1. Make sure you have an IMAP mailbox and SMTP server suitable for sending and receiving support emails.  Gmail will work fine, as will Google Apps mail.

2. Install the contents of the sp folder and all subfolders on a web server.

3. Visit http://example.com/sp/index.php (replacing that with the correct domain and path to your sp folder of course) and follow the instructions.  Make sure you uncomment and set the IMAP and SMTP constants in your config.php.

4. Log in as 'supportpressadmin' at http://example.com/sp/index.php and confirm that the installation worked.

5. Create a cron job to run sp/bin/spress-imap-pull.php at regular intervals.

6. Create a test thread by clicking on the New Thread link.  Send it to your own email address.  Check that replies appear in SupportPress when spress-imap-pull has run.