Instead of using multiple return points from a Language Select module (one for each language) and linking to separate Get Mail actions (each with an Entry Prompts in the required) language, you can use a single Get Mail action.
Through the Get Mail action's properties, record an Entry Prompts for US English users and save it as enu\custom\getmail.wav.
Record a similar prompt for French Canadian users and Latin Spanish users. Use the same file name each time and save each file in a different language folder.
ADDITIONAL INFORMATION:
Delete all except one of the entry prompt entries. That this does not delete any of the recorded prompts.
For the remaining entries, change the file path by inserting $LOC in place of the language folder name, for example $LOC\custom\getmail.wav.