How can I export all emails from a Zimbra mailbox using the SOAP API?

The export is performed via a GET request to the endpoint `/home/{mailbox}/?fmt=tgz&filename=...`. The mailbox user is URL-encoded (e.g., `admin%40test.com`), and the filename includes a timestamp. The response binary content is saved as a `.tgz` file. For details, see the Zimbra SOAP API Development Guide 4 - Email Export and Folder Sharing.