Each place is different (had a friend in jail recently). This seems to be basic rules.
Depends on if the jail lets the inmate get the physical mail or not (some are now scanning them and the inmate accesses them on a kiosk in their pod) but either way, expect the mail to be opened/read before the inmate gets it. Subject matter may also be limited.
They should be able to get letters; any cards must be devoid of any embellishment or layering. For example, can’t have glitter on it. Basically, you’re looking for 99 cent cards.
No packages, books or magazines.
Some allow money orders; others have a system where money can be deposited online for the inmate’s use.
TY, sounds like a generic letter will work. I wonder if they would pastelon letters that say that they are patriots. The FBI might intervene.