Personal "presorted" mail?

I notice that there is a cheaper postal rate for “presorted” mail. Well, heck 100% of the mail I send out is 1st class. Can I just buy those cheaper stamps, bundle my letters with a rubber band, and a piece of paper reading “pre-sorted 1st class” and drop that in a mail box?

Depends. How many pieces of mail do you send out at a time?


I was going to say:

I ask because rates for presorted first-class bulk mail don’t kick in until you reach something like 500 items. See here for more info.