Comment by zitterbewegung

Googling for a bit it seems like it depends on the state [1] and not the federal level. But, email can be sent or received using CORRLINKS but you have to pay a fee for sending and receiving. [2]

[1] https://en.wikipedia.org/wiki/Internet_in_prisons

[2] https://en.wikipedia.org/wiki/Trust_Fund_Limited_Inmate_Comp...