Consider the following figure from your textbook illustrating the steps and protocols used to send an email message from Alice's computer to Bob's Computer: Alice's mail server Bob's mail server Alice's agent SMTP Bob's POP3, agent SMTP IMAP or HTTP Figure 2.16 E-mail protocols and their communicating entities What service does Alice's mail server provide? Why is it necessary/useful to forward an email from Alice's agent to Bob's mail server through Alice's mail server