Mailalert -> new_order.html title

[User1234567891]

I am a bit lost.

I have altered the new_order.html in modules/mailalerts/mail/nl

when an order is placed, the altered dutch template is used, but the email title is still in Dutch.

In the nl.php file (modules/mailalerts)
the following line is visible:

$_MODULE['<{mailalerts}prestashop>mailalerts_9204d21640382a89a95ec42f44f9051c'] = 'Nieuwe bestelling:';

This should be the translation.
how do i know whether this number is corresponding to the mail template? Why does it not translate the title?

Hopefully someone can help.

Thanks!