First, modify bounce.cgi and signup-list1.cgi to contain your ListMailPRO URL. Then, upload them to your /cgi-bin directory and CHMOD (set permissions) them to 755.
Login to your CPanel control panel. Browse to the section Mail Management then Forwarders
Create two forwarding addresses, bounce and signup.
For each one, respectively, enter the following in the "Forward to" textbox:
- Replace username with your site / FTP username.
Note: Make sure the bounce and signup users are not set up as "standard" accounts. They should only be listed under Mail -> Forwarders in the control panel. Some cPanel versions seem to have a bug, or feature, where the mail storage folder is not deleted when you delete a standard mail account. If you delete an account that has the same name as one you want to set up as an alias you may have to manually delete the entire /mail/domain.com/account folder with FTP for email to be forwarded to the script(s) properly.
Next: Ensim (.procmailrc)
Related: Set up Cron with SSH, Test Mail Settings