The process of Alice's sent message to Bob is depicted as a series of numbered steps that move horizontally from left to right, and the numbers correspond to the preceding text. Alice appears at the beginning of step one and is depicted as a young woman in profile looking to the right; Bob appears at the conclusion of step six and is depicted as a man in profile wearing glasses and looking to the left. Between them are the six steps.

Step one is labeled "Alice's agent," and includes the desktop computer from which Alice composes and sends her message.

Step two is depicted as a blue arrow pointing to the right.

Step three is labeled "Alice's mail server," and includes an image of a server, the outgoing message queue, and three mailboxes, identical to the mail servers in the previous figure.

Step four is depicted as a blue arrow pointing to the right, labeled "SMTP."

Step five is labeled "Bob's mail server," and is identical to Alice's mail server.

Step six is depicted as a blue arrow pointing to the right towards a desktop computer labeled "Bob's agent."