For everyone's information....
I sent two samples off to Blackstone Labs two weeks ago and I received an e-mail report back on one of samples in a couple of days. The second sample was never received by Blackstone Labs as of yesterday.
So I drew another fresh sample yesterday afternoon packaged it and stamped it up (5 stamps) and delivered it personally to the main post office in downtown Chicago, as this location has latest pickup at 9:00 p.m., whereas the others are 5:00 p.m. although in reality much earlier.
Today I received yesterday's newly mailed sample in my mailbox, sent to me and not Blackstone. I drove over to a local post office and learned that the mail "reader" "read" my address (which is at the top of the canister) as the delivery address and it ended up being delivered to my house.
The clerk said that in order to avoid this in the future, don't write information on the sender part of the Blackstone canister which is at the top, just put a little preprinted address label there and the "reader" won't misread it. I will white-out all the lines in the top part and put one of the little preprinted name & address labels there from now on.
The post office put the canister in a large envelope, sealed and wrapped it with clear tape and will ship it priority mail at no additional charge to me.