How can I set up automatic bill pay from my checking account to deposit into somebody else's checking account? I know their routing number and account number, and the name of their bank (US Bank in this case). What address can I send checks to that will get automatically deposited?
Bill pay is sending checks to a certain address.
Direct deposit is depositing to a certain bank account.
What you need is "Direct Deposit". You need to talk to your bank on setting that up.
Alternatively you can set up a wire transfer, and in some banks they allow ACH transfers to external accounts that are not yours (in Chase, where I bank, they allow external transfers, but only to accounts that you own yourself). Check with your bank if they allow that.
ING Direct provides this service, I think it's just a disguised ACH transfer to another person's account.