If AcyMailing is not translated in your own language, you can easily add a language file in AcyMailing. Fist of all, you'll have to go on your AcyMailing configuration -> languages. If AcyMailing is not translated in your language, you should see a small Add Icon next to your language (only installed languages are displayed on this area so you have first to make sure the language file is installed on your website).
Click on the add icon and a popup will open, enabling you to modify the language file. If the language file already exists, you will be able to modify any string used by AcyMailing with this interface. If the language file does not exist, the English version will be loaded so that you can translate the strings from this English version.
Now that you are on the text area of the custom translate if you just translate several keys you won't be able to share the file with us, you will have to put all the keys in the text area.
So if you want to translate AcyMailing in an other language and share it to us click on the button Copy default translation
Once you translated your language file, you can click on the button Save. Then, if you want to share your language file with the rest of the community, please click on the button Share your transaltion.
Sharing a language file is very important so that we can include your language file in our next versions. Even if you translated only few strings, we would appreciate if you could share those modifications, so that you will be able to update AcyMailing without losing your work.