TeamViewer tries to determine the language for emails by using a best-guess heuristic. Among the options to choose from are the language in which you originally created your account, and the language of your last successful login.
Set up fix language
If you always would like to receive emails in a certain language you can choose the Email language in the Profile settings of the TeamViewer Management Console.
Note: If the language is not available for an email, the mail will be send in English by default. We are always working on making all emails available in all languages.
Note: All Remote Management emails alerts will be sent out in English only regardless of language setting.
Note: All emails to invite someone to create a TeamViewer Account are currently available in English and German only.