That will change.
I had one adopter who picked up a chinchilla from one of our foster homes. Also changing -- people adopting from foster homes will now be required to fill out paperwork prior to picking up their pet. Otherwise, it is too hard to chase everyone down once they already have the pet in their possession. I haven't had a problem until now, and of course I realize it's right around Christmas / the holidays, but now this is changing.
But back to addresses. The one person adopted from a foster home. After the adoption, I found some treats here that I specifically had marked as for that specific chin. I wanted to mail those to the new adopter, so I dug out her adoption form. The address was just a couple of numbers, but no street name. So I emailed the adopter. It took two emails and seven days for her to respond with her address. In the meantime, her husband (I assume? maybe family member) sent me the adoption paperwork... minus the adoption contract -- which ALSO would have had the address. They sent two copies of the health guarantee, but no adoption contract, so I emailed back that person asking for it. I still don't have it, and will chase down until I get it.
The thing is, though, I shouldn't have to. This shouldn't be this hard. When I found the treats, I should have been able to look at the adoption form and mail them out, without ever having to reach out. I also shouldn't have to contact the adopter, over and over, to get the correct forms sent back to me. So... this will all be changing. I will be eyeballing addresses from now on (not that this happens all that often, but two different people lately) and requiring paperwork prior to adoption in cases where the chins are at foster homes.