My site is in two languages, of which one is English.
Formmail and contact forms are located in three folders (apart from ini file etc. outside root folder).
Folder 1 (English): formmail.php + contact form.
Folder 2 (2nd lang.): formmail.php + contact form +
Folder 3: fmbadhandler.php + templates folder

2nd language is set up, and everything works perfect.

When testing the English version, error messages are shown in the wrong language! The "" takes precedence of the formmail script in a different folder.

Only one language possible per site?