I did the task already for you, send me a message.
b) Where and for how long is the email protected, and what kinds of protections are applied (e.g., confidentiality, integrity, non-repudiation).
It’sstored at the POP3 where the email is protected until client open or reads the mail. This helps against protection against pop up message notification that may expose one’s confidential message content and integrity. S/.MIME is used to offer protection for messages sent via mail.