Added configuration for Postfix to use an external SMTP relay with encrypted credentials managed by SOPS. Updated `mail.nix` to include relay settings and linked the secrets file for password storage.
Change the sopsFile path in acme.nix to point to the sgx directory instead of hetzner to ensure the correct configuration file is referenced. Added a new encrypted secrets file specific to the sgx directory to maintain security and confidentiality.
Harald Hoyer