I have a PHP script which checks the mail server for new messages.
If it finds a new message, it will process the message (and attachment) and store the data.
Once complete it archives the email and is done!

I want to automate this process using the cron.

HOWEVER, I just want to take into consideration the security implications.

1. What would be the best way to configure the script so that it were only accessible via a cron job?

2. If there was ever a need to manually process - what would be the best way to build an override that allowed me (and only me) to access and process the file?