[adnrw]

> And if all this still goes wrong... if the person liked your newsletter enough, they'll figure out what happened when they stop getting it.

Not necessarily, unfortunately. As an example, take emails advertising pre-sale tickets to events, sent to people who have signed up specifically to have access to buy tickets before the general public.

If their friend is able to unsubscribe them, they don't get the email and miss the pre-sale access. Even if they do realise and resubscribe, there's a good chance they'll have missed the pre-sale period anyway (which only lasts a few days).

That's one of many examples that make "not to worry they'll just resubscribe" not quite work properly.

> The best way to mitigate this is a simple "You unsubscribed [e-mail]", with a little undo button in case it was a mistake.

In addition to this, it's worth putting "This email was sent to [e-mail], unsubscribe by clicking here" in the email.