1. Click on the file you want encrypt with the right mouse button, select 7-Zip and click on „Zu einem Archiv hinzufügen…“
2. A new window opens. Enter a password.
3. A zip-file is created which contains your file that can only be opened with your password:
4. Send the encrpyted zip-file by E-Mail and communicate the password to the recipient separately (by phone, by separate E-Mail)