Usps pick up does Usps first class package include security envelop

[davwardrobe]

I was wondering if usps first class package also count first class letter as part of its service. The last time I request a pick up for first class package and they charged the buyer with shipping fee.

[partial*eclipse]

Letters aren't packages.  If you put a First Class package label on a letter, if can get upgraded to Priority Mail due to the tracking.