The grading process may take up to several weeks. You may well have returned to your home countries by the time your graded certificates (Scheine) are available. This should, however, not be a problem. Just make sure you keep the contact details of your professors safe and that you provide them with an alternative email-address in case your FU email address expires. Stay in touch with your professors and, if needed, remind them to send you the graded Schein via email. Alternatively, professors may send them to the OSI Erasmus office directly.