usps to apo's only

I'm sure this has been covered but I can't seem to find for whatever reason. I ship by UPS only, but would like to be able to ship to Military APO's by USPS only. Can I install USPS shipping for military Apo's only? Making the default shipping UPS unless a Apo zip is entered then using USPS?
Thank you

Create a Zone Definition where the Details for it are those specific locations ...

Then, install the USPS shipping module and add that new Zone Definition to it so that only those with shipping addresses in your defined Zone Definition can see it ...

Thank you for your help. I have them set under locations/taxes Zones. Do I need to create zone definitions for each Apo? or can I do it with one. The zones are AA, AC, and AE.

They should already exist in the default Zen Cart ... in the Locations / Taxes ... Zones ... around page 7 ...

What you need to do is go to the Locations / Taxes ... Zones Definitions ... and insert a new Zone Definition name and then define the Details to include these specific Zones to it ...

Once the Zone Definition is created so that it includes each of these, you can add it to your USPS shipping module so that only the shipping addresses for this Zone Definition can use it ...

Thanks again for your help, I got the zones set up installed USPS, got an account with username and moved to production server but can't get USPS to work site shows..
"Error: Shipping Methods not configured
usps (ignored)"
I'll search around for a solution.

update, I have found that when I do not select a zone with USPS it works, when I try to add a zone like "APO" it doesn't work so I guess I didn't create my zone properly

sorry not trying to bump, just been working on this and have found that the problem seems to be with google checkout, if I tun off google seems to work. But once I use google and USPS with zones, google give error message. Frustrating!!

Sorry ... I am not real familiar with the Google Checkout ... you might look in the support thread for it ...