The Conference of Data Protection Commissioners (CDPC) of the Bund and the Länder has published a guide for the private use of email accounts at the workplace. The CDPC reacts to the increased use of private email accounts at the workplace and the increased requests  of how to deal with this problem by employers. The guide is directed not only to private employers, but also to employees, work councils and public authorities. One of the main proposals is to provide a written agreement between the company and its employees on the private use of the Internet and/or the company email account.

CDPC Press Release

Guide on private use of email account at work (PDF)