This topic missed the Redux thread somehow, but I find that if you treat postal employees with respect, they will go out of their way to accomodate you, especially in small markets. Some will even bend over backwards to be helpful.
If you start the relationship with a vulgar complaint, they may be inclined to bend over forward and do an about face.
Two thumbs up from me for the USPS. I use UPS and FedEx too infrequently to know their habits (forward or backward?).
