The client clicks the link. The browser decrypts the file locally. They download the 6GB RAR, enter the password you told them separately, and extract.
This size immediately blocks standard email attachments (usually limited to 25MB) and pushes you into "large file" territory. The client clicks the link
Wormhole is one of the fastest ways to send large files with end-to-end encryption. Up to 10GB for free. The client clicks the link