Which goes right back to what OP was saying, it's not taking into account how email actually works. The user did not mark it as spam, contrary to what you said

Which goes right back to what OP was saying, it's not taking into account how email actually works. The user did not mark it as spam, contrary to what you said earlier - they never even saw it. It's not even close to the same thing as the recipient tossing physical mail into the trash without opening it.