it's 50/50, some mail room staff will only deliver the mail to the inmate with an inmate ID number. we highly recommend having an inmate ID number for all correspondence.
https://www.inmateaid.com/ask-the-inmate/will-an-inmate-get-a-letter-if-i-dond-have-an-inmate-number#answer
Accepted Answer Date Created: November 13,2015