STARS: Mailing Money Orders and ensuring their destination

Some of you know I handle my incarcerated uncle's money and am his power of attorney. I am also my mother's although it isn't official. If you're tracking, that's 4 accounts I watch (counting my major two). 

I almost messed up big time this month with my uncle but I made it right and everything ended up well. 

I correctly address and stamp a bunch of envelopes, as far as six months out. I even write the check out the day before so I can cash it the day following. 

I take the cash and then go to the USPS office and get my money order. I keep the receipt in a safe place until I confirm that my uncle has his money. 

I subscribed to the USPS digest about two months ago. This lets me know what is supposed to be coming to my mailbox. It is usually that day but I learned that if it's a return to sender case, it may be up to two weeks before you receive the letter.  That's why I found it better to have the address correct the first time down to the number and even send the money order early to have a larger window. 

I then receive verbal confirmation that the money order is received and I can discard the receipt if desired. I then prepare for the next month.