Understanding the Basics of Email


Though you probably send emails on a daily basis, understanding how email works come in pretty handy as we discuss some of the more technical components of email marketing in future posts. To best understand how email works, let’s first think about how sending a letter in the mail works.

Imagine that Sally wants to send a letter to her friend, Joe. To begin, she writes him a letter, encloses it in an envelope, affixes postage, and places the letter in her mailbox. From here, the postal service steps in and handles the end-to-end delivery, retrieving the letter from Sally’s mailbox, moving it across town — or across the country or around the world — and delivering it into Joe’s mailbox. With email, the process is pretty similar, with the main different being that there is no single entity, like the postal service, to handle the end-to-end delivery of the message.

Instead of a letter, let’s imagine that Sally is sending Joe an email. Let’s also assume that Sally uses Gmail and Joe uses Yahoo! Mail.

Sally composes a message, addresses it to Joe and clicks send. When she does, the message is handed off to Gmail’s SMTP sever. (SMTP stands for Simple Mail Transfer Protocol, though that isn’t really important right now. Think of the SMTP server as a delivery man.)

From there, the Gmail SMTP server (delivery man) tries to make a connection to Yahoo’s SMTP server (delivery man). Assuming Gmail’s server can locate and connect to Yahoo’s server, what follows next is the equivalent of conversation between the two servers — again, think delivery men — that goes something like this:

Gmail: Hi, Yahoo! I’m Gmail.
Yahoo!: Hi, Gmail. It’s nice to meet you.
Gmail: I have a message for Joe from Sally.
Yahoo!: Ok, thanks! Please give the message.
(Gmail sends the message to Yahoo!)
Hi Joe,
I wanted to confirm that we are on for dinner at 3:00 pm on Tuesday.
– Sally
Yahoo!: OK, I’ve received the message.
Gmail: Goodbye.

Now, the conversation that actually occurs between the servers is much more technical and less human-readable, but that’s the gist of it.

Understanding the basics of how email works will come in handy in the later posts, especially as we discuss some of the things that can and do go wrong in the realm of delivering emails successfully.

Note: This is from a book about email marketing I started working on a few years ago that I’m not likely to get around to finishing. 🙂