The difference between direct and indirect supervisor is the presence of the supervisor. Direct supervision means a supervisor is psychically present.
When mailing a certified letter, a person should expect it to take from three to five days to reach its destination. Depending on how long it takes the recipient to pick up the letter, the process can take up to 21 days. People who send certified mail receive a notification to prove that the letter has been received by its recipient.
Certified Mail can be sent to a P.O. Box. When the Certified Mail arrives at the delivery Post Office, the letter carrier will place a delivery notification inside the P.O. Box that instructs the person to present the delivery slip to the window clerk.