The page you requested in unavailable without a network connection.
This offline page is a good place to have a collection of useful information such as phone number(s), address, hours of operation, etc. Even though the user is not connected to the Internet, listing email addresses here is still useful as drafts can be saved locally on their device.
If you have pre-cached PDFs or other files, linking to them here (and mentioning they can be viewed offline) is another good idea.