Generally speaking, prisons consider mail sacred and will do whatever they can to deliver it to the person it's intended for. They will make ever effort to connect the name on the envelope to a recipient at their prison. The basic connection to someone on the outside is seen as a crucial element to rehabilitation and the goal of not having the inmate come back.
https://www.inmateaid.com/ask-the-inmate/i-have-sent-several-letters-but-i-did-not-have-an-inmate-number-do-do-you-think-the-prisoner-still-received-the-mail-i-sent-him#answer
Accepted Answer Date Created: February 01,2013