https://www.pochta.ru/support/post-r...eiving-sending
First of all, small letters without declared value or mark 'poste restante' are delivered to mailbox and anyone who have key can get it.
Otherwise you will get notification only and have to visit post office with passport to get it.
However it is normal for 'Sarah' to get passport of 'John' and receive package without his presence at post-office. At least I did it multiple times.
Another option is 'letter of attorney', but this is unusual thing for private individuals.