Oh no, not the postal workers! Some of our most beloved cultural icons are postmen!
What about Cliff?
...or Mr. McFeely?
...okay, forget about David. Still.
You want to deliver the mail? FINE, go 'head!
"No I'm not, no mail on Sundays."
This guy is taking, "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds" literally.