Update: Surendra Malu writes in:
Your latest post reminds me of my personal experience.
I was supposed to receive a congratulatory letter from Maharashtra Govt. for my success in an exam that I took in fourth grade. This letter was sent out at the start of my fifth grade. It reached me when I passed a similar exam for seventh grade i.e. I received it in 8th grade. The letter was sent from Mumbai to my residence in Kolhapur.
In this case, even a snail would have done 10 rounds of Mumbai-Kolhapur distance.