Try copying and pasting the spanish content of emails.php into the English file you have copied into the folder es_uy.
This is:
1.- Unzip the OpenGoo installation in a temporary folder
2.- Find and open emails.php in es_uy folder (in the recently extracted folder)
3.- Copy the contents to the clipboard
4.- Open emails.php int the es_uy folder in the OpenGoo working installation
5.- Paste from clipboard, replacing current content
6.- Save
7.- delete temporary OpenGoo installer
It is not the ideal solution, but it should solve the encoding problem.
Marcos
PS: Let us know if it works