How Email REALLY Works: what every Modern Marketer should know

By Maria Shull

With technology and evolution in general, we seem to take for granted some things for which previous generations have set the stage. The things our elders have made simple. Convenient. A matter of fact. Email.

History tells us that our communications have evolved from cave paintings in 30,000 BC, to the present day Internet and email. The first commercial email was sent in 1978, before the idea of Opt-Out or SPAM were commonly talked about. Hotmail launched a free email service in the 1990’s and we thought the Internet would fall apart in Y2K!

So with years of technological experience behind us, what our predecessors put in motion is something we all seem to take for granted. The simple sending of an email. I say simple, but it’s really a compound process that occurs in the matter of seconds!

  1. You compose an email invite to send to your best business partners for a luncheon during your annual sales event.
  2. You press SEND, and your email is deployed to your guest list.
  3. You begin receiving the RSVP’s immediately. That was fast!




But what goes on behind the scenes is amazing! And a lot more complex. If you understand more about how it all works, you are a better marketer with the intelligence to know how to get your emails to the Inbox. Oh and that whole branding and deliverability topic will make a lot more sense.

The internet is the framework or launch pad to send an email communication. After pressing Send we think, “DONE!”, but in fact, this is what happens:

How Email Works

  1. Your email is sent from your email client or Mail User Agent (MUA) to a Simple Mail Transfer Protocol (SMTP) server via a Mail Transport Agent (MTA) – kind of like the mail truck that moves emails.
  2. At the SMTP server, we can think of this as the Post Office, it checks your return address, and sees the address you are mailing to.
  3. Your email is sent to a DNS Server (Domain Name System) which looks up the domain or address to verify its existence and translates the address into a series of numbers referred to as an IP (Internet Protocol) address. It goes a step further by verifying that the receiving address has an MX (mail exchange server) record so the invitation can be delivered. In essence, it makes sure our guest is still at the same address.
  4. If the email passes the checks in the DNS server, it then moves to the MTA which again, is our delivery truck.
  5. The recipient’s MTA then delivers the email to the incoming mail server (called the MDA, for Mail Delivery Agent), which stores the email as it waits for the user to accept it. There are two main protocols used for retrieving email on an MDA:
    1. POP3 (Post Office Protocol), the older of the two, which is used for retrieving email and, in certain cases, leaving a copy of it on the server.
    2. IMAP (Internet Message Access Protocol), which is used for coordinating the status of emails (read, deleted, moved) across multiple email clients. With IMAP, a copy of every message is saved on the server, so that this synchronization task can be completed.
  6. Finally, the recipient views and opens your email via the MUA aka email client which is a tool like Outlook, Gmail, Apple Mail, Lotus Notes, etc.

But is this still your perception?


And do your reports and analytics have a similar simplicity?

Digging into deliverability reports (hard bouncebacks, soft bouncebacks, and global unsubscribes) and sender scores (available for free through will reveal hidden gems of information that can transform how effective your email marketing can become.

Find out your Sender Score. Find out how simple changes to your email marketing can boost your marketing automation ROI. And when needed, ask for help from your Eloqua email experts like us!

About the author:

Maria Shull

Marketing Automation Consultant