I have some people that may end up sending me letters that arent on the approved list. What do they do with those letters and will they tell me they received them so I can try to start the process to get the addresses approved.

You can get mail from anyone, providing it isnt inmate to inmate correspondance. It doesnt matter if its from people not on your approved visiting list. Sometimes ive even forgotten to put a return address on the letters to my fiance, and he still gotten them. I realised AFTER putting them in the mailbox

PS - Inmate to inmate correspondance has to be approved by the warden.

I've written to several people that I'm not on their visiting list...my mail has never been rejected.

Everyone is right that anyone can write you except other prisoners. IF a letter is rejected for some reason by the BOP, it is returned to the sender and a written notice is supposed to be sent with it, listing the reason the mail was rejected. A copy of that Notice is given to the inmate so they know that mail was rejected and the given reason. Z.

Note on Zelda50's comment.

Mail if rejected is suppose to be returned with a notice, etc. However, sometimes I guess they just trash it or something because they do not always return it or notify the inmate.

Note on Daisy1313

We've never had the problem of something just being trashed and no notice sent. Believe me, I have my fair share of notices here that did come back with the original contents. It's worse then getting the past due bill collections! :D

Now...things have been lost in the USPS and have even turned up close to a year later. I received a letter thinking...what has he lost his mind, then when I looked at the postmark I seen it was the letter he swore he mailed early in the year...it had just arrived!