The U.S. consulates in Germany have introduced a new process for applying for a visa by mail, without the need for an interview with a consular officer.
First, an invitation to apply by mail is sent by email, with the relevant documents attached. After the consul determines that the applicant meets the requirements to apply for a visa by mail, a confirmation is sent by email with instructions on how to proceed.
The categories of visa applicants who are eligible to apply by mail have not changed.