"Pocket query"?

Huh? Wuzzat?

"Importing a Geocaching file
The easiest way to start geocaching with an Android phone is to have a pocket query sent to the email address on you phone. Here we click the Preview button on the attachment to start the import."

Please excuse my ignorance - I have heard of geocaching, and I can imagine that a .gpx file contains information about one or more caches. But how do I download a .gpx to my gmail? and from where?