I have to admit, I got burned. I was in rush one day last year and needed some stamps for the holidays. I ordered some on line from what looked to be a US postal site. It wasnt, When I got the stamps, and saw the mailing address they came from I realized they were not legit. They looked legit but when I looked into it, counterfeit stamps are a thing. I never used them but up until today, in theory the mail would be returned. As of today, May 7th, the postal service will just throw the letters and packages away. The change is buried in this postal bulletin https://about.usps.com/postal-bulletin/2023/pb22622/pb22622.pdf page 4, upper left hand paragraph.
From some other folks who got burned, the local postal clerks may or may not be able to distinguish them but auto sorted mail (almost all mail) do.
I have a large box of old low denomination stamps that are only worth face value (no collector value). On occasion I use them up. Some are from the seventies and expect they are not marked with the UV ink used to by the sorting machines to detect the fakes so I wonder if older envelopes stamped with old real stamps will get checked.
Reportedly, the post office isnt really trying really hard to deal with the counterfeiters who make and market these stamps.
From some other folks who got burned, the local postal clerks may or may not be able to distinguish them but auto sorted mail (almost all mail) do.
I have a large box of old low denomination stamps that are only worth face value (no collector value). On occasion I use them up. Some are from the seventies and expect they are not marked with the UV ink used to by the sorting machines to detect the fakes so I wonder if older envelopes stamped with old real stamps will get checked.
Reportedly, the post office isnt really trying really hard to deal with the counterfeiters who make and market these stamps.