Download This Script: 
Watched Folder Script
on adding folder items to this_folder after receiving added_items
try
repeat with EachItem in added_items
set ItemInfo to info for EachItem
if not folder of ItemInfo then
set FileExtensionOfItem to name extension of ItemInfo
if FileExtensionOfItem is "xml" then
tell
application "Endicia"
process XML file at (POSIX path of EachItem)
end tell
end if
end if
end repeat
end try
end adding folder items to
Save this script to the Folder Actions Scripts folder in the Scripts folder.
Then create the folder you'd like Endicia for Mac to watch. Control-click on it to bring up a contextual menu where you can enable folder actions and then attach the above script to the folder.
Save a valid XML file (sample) to the folder and Endicia for Mac will automatically process it. You may want to turn on the renaming of processed XML files preference which will change the extension to .BAK after the file has been processed.