We estimate that it takes about 3 business days to arrive in the
facility mail room. Once there, the staff opens each piece for
contraband. Be mindful that each facility has their own set of rules as
to how long they have to actually deliver the mail. For instance,
the CDCR in California has up to 14 days from receipt. This is a drastic
example, but the prison business is not normal and the rules are like a
moving target.
https://www.inmateaid.com/ask-the-inmate/how-long-does-it-take-for-the-inmate-to-receive-his-letter-once-its-sent.amp#answer
Accepted Answer Date Created: April 10,2014