Postal workers - reputation earned

I just found out that a time-sensitive legal letter I sent via registered mail on Friday afternoon has not moved from the original post office. The reason? Someone at the post office wrote a postal code on the envelope for a northern ontario town. I had written the complete address and it didn't include a P-something postal code. Even if I'd left it off by accident, Oakville On is fairly easy for someone in the Mississauga post office at Turtle Creek to figure out. So frustrating.