I hope you're nicer than the clerks at my post office. They are always rude.

But you could always produce a machine gun and go postal.

How about a costume change at the end?

Do a coloring book with stamps? Turn Money Orders into cash?

Human scale tricks.

I came up with a partial routine a while back using a character, the Magical Mail Man. Some tricks that could be used are a Stack of Boxes usingpacking crates. Pretty much any illusions with cardboard boxes or packing crates. I was thinking about doing an appearing illusion from boxes, like appearing poles or bowling balls, etc.
-Tyler

Not only could you do a Lepaul Card to Envelope in a wallet but also in a stack of letters which could be secured by those standard postal rubberbands for authenticity.

You could perform the POSTCARDS FROM THE ROAD.
PM if you would like more details.
-Jared

You could possibly work out a large color-changing stamp routine or some "stamp manipulation" with very thin, card-sized, cardboard stamps. A stack of packages effect would be neat as well. Another idea would be to use a multiplying dots routine with a letter inplace of the domino card and stamps in place of the dots.
-Michael