Postal Worker Picking Up and Dropping Off the Mail
After the postal worker has picked up your mail, he brings it
back to the local post office. Eventually, your letter gets to the post office
near your friend to whom you are sending the letter. At that point, the local
postal worker at the destination puts the letter in the PO box at your friend's
place, where he can pick up the letter when he gets home.
Simple and unsurprising, right? Well, e-mail works similarly.
If you were to create and send an e-mail to your friend, your PC would not
actually send the e-mail to your friend's PC. Instead, you would send the
message to your e-mail server, which is the equivalent of dropping off a letter
at the local post office. Your e-mail server would send the e-mail to your
friend's e-mail server, which is the equivalent of the postal service delivering
a paper letter to the post office near your friend. Then, at some point in the
future, your friend would check her e-mail and retrieve the e-mail from her
local e-mail server, which is the equivalent of retrieving her paper mail from
her PO box. Figure 8-2 shows the same
basic flow as snail mail, but instead now for e-mail, with Keith sending an
e-mail to the sales department at fredsco.com (email@example.com).