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.
Priority Mail is the United States Postal Service's standard air service. Packages usually arrive to their domestic destination within 1-3 business days, depending on how far the package has to be delivered from its origin.