Post office return address?

Question

I'm helping a friend send a letter to this company. On the letter it's her address and name of course. My friend and I live in different states. She just moved to New York and I'm from California. But since I'll be sending it for her can I put her return address as well? Would the post office care that they are sending a letter from California and having New York as a return address? Can we do that? Thanks I just wanted to know. Any valid information would be helpful!

Answer 1

The return address has nothing to do with where the letter as sent from.  That is documented by the postmark.

The return address is simply where you want the letter returned to in the event that it's undeliverable.