The primary alternative is to have signed delivery, in which case some people will simply refuse to sign it and thus prevent delivery. Signed delivery is the way the postal service usually differentiate between normal delivery which has some kind of error rate which the postal service do not take responsibility for, and the signed service which usually carry some insurance (up to a maximum) of delivery.

The US has their Service of process which is commonly seen in movies, which is often made into a joke in comedies.

A much older system is the one where by law people had to put a notice in the news paper, sometimes multiple notices, and then that was considered enough proof of delivering the notice.

It would be an interesting conversation to philosophy how a future system should be designed that can't be refused, where delivery to the recipient is guarantied, and where the sender and the delivery service must produce proof of their parts.