In the US, some banks generously offer a "bill pay" service, which is an online page that allows you to mail a (paper) check to a US address. Most banks don't change for this service, which "saves you a stamp".
However, in contrast to hand-written checks, the bill-pay checks get funded immediately when they are sent, not when they are cashed. Occasionally, a check might never get cashed, because it gets lost in the mail or the recipient fails to cash it for whatever reason. When you send a hand-written check, it will expire and you end up not paying. What happens when the pre-funded bill-pay check gets lost? Does the bank refund the money that was never claimed at some point, or does it get to keep it?
Edit: both Chase and Bank of America withdraw the money from my checking account the moment I hit the "send check" button. I never get to see if/when the check has arrived or has actually been cashed by the recipient. I am asking this question because I sent a check two weeks ago, and the money has been withdrawn from my account. However the recipient today told me they have not received anything. So I am wondering if the bank would every let me know if the check got lost.