Subscribe by e-mail translation

Hello.

I'm having problems translating the e-mail that is being sent by the "Subscribe by e-mail" plugin. Did anyone here successfully translate the e-mail text?

The plugin page in wp-admin is translated, but the e-mail is in english. I've tried translating it inside the plugin file but åäö or its html tags is coming out wrong which kind of ruins that idea.

If anyone successfully translated this, please explain how you did it. If not, my request is that it becomes translatable.