In order for the script to receive e-mails, an e-mail account (mailbox) must be available. It is important that the e-mail account is configured as catch-all. Each web host handles the catch-all feature differently. Please contact your web host about that, if you do not know whether your web space package supports catch-all or how it can be turned on.
If your web space manager is called "cPanel X" you need to create a mail account first and then go to Mail >> Default Address. If there is nothing set yet, click on the link "Set Default Address" and enter the name of the e-mail account you want to use with the script.