There has been much discussion regarding sending letters to SR's in boot camp via the SANDBOXX App.
Here is information I have received from RTC:
"While RTC does not endorse or promote the app, recruits are most certainly welcome to receive letters sent through them.
The RTC mail room does not deal with ANY FedEx or UPS mail (Sandboxx falls under this category). They strictly only deal with misdirected mail, such as wrong addresses or ASMOs. All mail that the post office on the main side of the base deals with goes straight from that post office directly to each ship. There, it gets sorted by division. Any mail for a recruit no longer in that division then gets sent to RTC's mail room where the two staff members must look up each individual letter in the computer to find the correct division for that recruit. Those letters are then sent out for redelivery. Thus, which explains such letters get delayed. Plus, anyone sending letters to a recruit whose division isn't even in their permanent ship yet will also have their letters sent to the mail room. Which is why we constantly stress: wait for the form letter! Especially if the recruit gets ASMOed from failing baseline PFA.
Which bring us to the FedEx letters. Because the mail room is only authorized to deal with USPS mail, any letters sent via FedEx or UPS which cannot be delivered due to a wrong address, get sent back to the carrier. "
So you may continue to use the Sandboxx app but keep in mind IF your recruit changes divisions for any reason the letter will NOT be forwarded to them - it will be returned to you. And remember someone else (at Sandboxx) is reading your personal letters and has access to your information.
To clarify - it is important to wait for the formal letter to send mail to your recruit whether or not you are using Sandboxx or USPS.
Also - it is not recommended to use the Sandboxx APP after they finish boot camp and are in the fleet. Use of Sandboxx once they are in the fleet has been known to delay homecoming. Please consider this once they are out of boot camp.
Hope this clears up some of the confusion!
Here's the link to the app:
**Updated info September 2022
September 13, 2022
I also received an email back from RTC this morning regarding the Sandboxx App and everything is confirmed. If your SR chooses Sandboxx then you will NOT receive a hard copy of anything. All necessary info will come from Sandboxx and it will direct you to their website where the info will be, or you can go RTC's website. If your recruit opts out of Sandboxx then they are SUPPOSED to be receiving the hard copy of the family letter to mail home. I was told there was a slight snafu where that wasn't happening for some of the recruits, but it should have been rectified by now.
And just to clarify - there is a cost to use the Sandboxx App. 1 letter is $4.50 to send. They do offer discount plans for multiple letters.