Internationalization of Subscribe by Email

Hello.

I'm trying to translate the subscribe by email plugin and I am unsuccessful.

Since the plugin doesn't have a textdomain I am translating it in the php file. However, when a mail is sent out characters like åäö can not be displayed.

I started off by using the html code for the characters but the email is printing them out. I then changed from the html code to the actual åäö, but the email won't pring them out correctly anyway.

Does anyone know how I can fix this? My script to add textdomain doesn't work for some reason so I can't add textdomain to these plugins manually any more.