Puzzling. Can you post a screenshot of the copies&folders pane? Is this IMAP or POP? If IMAP, please rightclick on account in folder pane and select 'subscribe' to see if the sent folder is checked. Also, send a message to yourself to verify that the send is working. Let us know. thank you.

Das ist alles in pop.

der Versand funktioniert schon, ich kann es nur nicht überprüfen. Danke

OK, I see the send folder, and when you click it, nothing happens? I would check the copies&folders pane to verify settings, and I would also check the folder in Windows File Explorer (assuming you use Windows) to see if the size of the folder and last date of change indicates that the messages are being saved. Otherwise, I have no idea. I have never seen your situation before. Maybe somone else will have suggestions.