Prison Pulse Report

I have been writing to various synagogues (I am Jewish), asking for prayers and support, Presidential commutation and prison reform. Apparently some guards here do not like the idea and have begun returning my outgoing mail, saying the first class Forever Stamps are invalid unless they are the “currently issued” ones. I thought forever meant we could use them anytime and they would still be valid? They change designs all the time and all the designs are still valid.