Endicia for Mac Walk through:
FileMaker AppleScript to Get Confirmation Results

You can create a simple script from within FileMaker Pro to ask Endicia for Mac the results of a package you've shipped.

Below is a sample script:

tell application "Endicia"
   track "9101148008600025293979"
   set a to the result
   set t to item 1 of a
   set the clipboard to (t as text)
end tell

tell application "FileMaker Pro"
   activate
end tell

By creating a calculated field with the above text (and appropriate fields from your database where the tracking number is), and performing an AppleScript on that field, you can do more with Endicia for Mac without leaving FileMaker Pro.