With a cashier’s check, it’s mitigated because the check is written from the bank’s account. With a certified check, that risk is mitigated because the bank has set aside the amount indicated. This puts you as a recipient at risk of not getting the payment you expect. When you take a personal check as a payment, you don’t have a concrete way of knowing whether the account it was written from has enough money in it to cover the amount. Which is safer? And how do you avoid fraud?