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.
As of publication, mail sent via Certified Mail service can take up to five business days to reach its destination, and mail sent via Registered Mail service can take up to 15 days. If you use insurance with Registered Mail, the delivery can take up to 21 days.