Are you Previewing your Pocket Queries before selecting a day for them to run? Are there caches in that Preview? If there are, you should receive a .gpx file containing all of them. I wouldn't "waste" an emailed Pocket Query on one with only ten caches in it, although you can Preview your results for only ten caches to make sure you area getting the caches you expect to receive.
Here is how I set up one part of the PQ form:
The two biggest problems with empty PQs usually involve using "Home Coordinates" as a choice, along with a single State. Also, choosing any Attributes, or all of them, causes problems with PQ results.
Good Luck!
Yes, I am able to preview them. I actually just tried using MacCaching on my Mac, to see if it is an issue with my PC. Believe it or not, it actually gave me the same message..."file empty". I wonder now if it is an issue with my email server, perhaps it's not importing or transmitting the files correctly? Currently Geocaching.com sends emails to my work address (as I do geocaching with my students) which I can access both at home and at work. I have it sent there as, due to firewalls, I am unable to access my personal email at work. Also, due to work email security, sometimes attachments don't work. I wonder if I have the PQs sent to my home email if I would have the same issues?