Write your letter on something misshapen and unconventional. Like on the back of a grocery sack. 8. Big envelopes have to be torn and sorted differently than regular business-sized ones. An added bonus to the big envelope is that they take priority over other mail, forcing them to hurry up and deal with your mess first. Always put extra paper clips on your forms.
Any foreign fasteners have to be removed and put away.
Sign your name in ink on every page. Any signature has to be verified and then date stamped.