They must go to the Post Office to Sign for the letter and pick it up. If no one picks up the letter after 5 to 7 days, USPS will leave a second delivery notice. Again the delivery slip reminder is left by the letter carrier. Finally after 5 to 7 days the third and final delivery attempt is made to the delivery address.
Gamma-cyhalothrin is a single stereoisomer of the pyrethroid insecticide cyhalothrin, and as such shares physical, chemical, and biological properties with both cyhalothrin and lambda-cyhalothrin, which are mixtures of 4 and 2 isomers respectively.
Cyanocobalamin, in summary, is a low-grade, low-quality and slightly toxic (cyanide) form of vitamin B-12 that's used by all the cheap vitamin manufacturers. I recommend avoiding it completely. It won't kill you to take it, of course, but there's a better solution for B-12.