I use Stamps.com, print my own postage, my mail lady (a good friend) picks them up from me and takes them in with her. They miss front counter scrutiny and 95% of them get to the Buyer. #00 Padded envelope with 1 or 2 chips = $ .99

I believe if you give the envelope to your carrier, they get into the Post Office in a different manner than if you take your envelopes to the front desk OR put them in a public mailbox.

Rich