Thanks to the guys at the Admiral Junction Mailing Center for solving my problem! I had taken a check to another mail house on Saturday and paid $20 for what they told me would be overnight (delivered on Monday). However, the person who was to receive the check did not get it. Apparently, they had sent it FedEx Ground for delivery the following Monday (even though I was clear about how soon I needed it to get there!).
To fix the problem and really get it there overnight, I was now quoted $65. The folks at Admiral Junction Mailing Center hooked me up for half that…thanks for being honest and clearly explaining my options!