0x44

    * A protocol that leaks metadata, including some message content, at the envelope layer.
  Could you elaborate more on this? I don't really understand what you mean.

  EHLO your.mx.example.tld
  MAIL FROM:<[email protected]>
  MAIL TO:<[email protected]>
  DATA
  From: Definitely Not Bob <[email protected]>
  To: Probably Not Alice <[email protected]>
  Date: Mon, 12 June 2017 16:02:43 -0500
  Subject: Super Secret EMAIL! Don't let Eve see!
  
  -----BEGIN PGP MESSAGE-----
  ...
  -----END PGP MESSAGE-----
  .
  QUIT

    movq $0x2000004, %rax  ; // BSD syscalls are divided into classes.
    movq $1, %rdi          ; // 64-bit registers use %rdi instead of %ebx
    lea message(%rip), %rsi; // Relative Address of message
    movq $13, %rdx         ; // Same Length
    syscall                ; // x86-64 ASM syscall

    movq $0x2000001, %rax  ; // Exit Syscall
    movq $0, %rdi;
    syscall

    message: .ascii "Hello World!\n";