The download file is a zip archive (.zip), which you will need to unzip once it is downloaded. The downloaded file can be found in your web browser's download folder. After the file is unzipped, you should have a folder named "POP3it_Pro6_3".

The files in the folder are as follows:

CNS Plug-ins License Agreement.pdf

This is the license agreement for the plug-in.

POP3it Pro ReadMe.rtf

This file gives more information about the plug-in, including the changelog that shows what was updated in the most recent version.

POP3it Pro Installer.fmp12

This is the Installer database. Open this database to install the plug-in. It also includes links to the POP3it Pro documentation and example databases.

Now you have the plug-in files, continue installing the plug-in.