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.
At the first delivery attempt, if there is no authorized recipient available to sign for the letter, USPS will leave a Notice (PS Form 3849) informing the recipient that a piece of Certified Mail is waiting to be received/signed for at their local Post Office.