The only way you will know if they received it is when they respond back to you, thanking you for remembering them, unless the letter is returned to us. In that event we will investigate the reason and notify you of your options. It's rare but sometimes the facility is wrong or the inmate ID is missing. These are all correctable and we do so at no charge.
https://www.inmateaid.com/ask-the-inmate/how-do-i-know-that-my-inmate-has-received-the-letter-postcard-photos-i-sent.amp#answer
Accepted Answer Date Created: July 28,2016