first of all, many thanks for your work.
I found your plugin installed in a theme, but I have a problem: my site use Wpml and I customized all messages for all languages, but when I try to register my email, only english messages is showing.
Can you help me, please?
It could be the registration form not generated by Newsletter and missing the current language the user is using to visit your blog. Try with a generated form, for example staring from the newsletter dedicated page.
Are you using the latest version of Newsletter?
I’m usign the minimal widget, in all pages of my site. the url is http://devstorefarchioni.testsuite.tk , the form is at the bottom of all pages.
I tried to edit the minimal.php code and the language is correctly detected.
Many thanks for your help!