True, but the nice thing is it that allow-lists can be handled transparently by your email client. Never saw this +string before? Mark as spam. Is the +string

True, but the nice thing is it that allow-lists can be handled transparently by your email client. Never saw this +string before? Mark as spam. Is the +string missing? Spam. Recognize this +string from your "Sent" folder? Keep. Signing up for something? Generate a pseudorandom +string and add it to the allow-list.