Ever wonder what happens to your email after you hit send?

An easy explanation of the complex world of email delivery

Every day, Emma customers log in, create campaigns and send them to their audience. For most of you, that last sentence is not a summary of the process as much as it is the process, as far as you’re concerned. But, did you ever wonder what actually happened when you hit send?

Before I started my career in email delivery, I imagined sending emails looked like some sort of Rube Goldberg Machine: a bowling ball rolling down a track, opening a door that pushes a knife into a string, releasing a mouse that takes the cheese off of a scale, which then unweights and causes a small explosion — no, a huge explosion! — to propel said email to the other side of the Internet. In reality, it turns out it’s surprisingly similar to this model.

There are a ton of pieces to the email-delivery puzzle, and the first piece is you. It could technically be your content, but in chicken-or-the-egg situations, I lean towards the one with ambulatory ability. So, you create your campaign, save and proof it, but then what? Well, the short story is that Emma takes that content, wraps it in your stationery and then sends it to one of our “mailers” (technically an MTA). The mailer adds the email header information that identifies: the email’s sender (also known as the RSVP address), where the email is being sent from (our servers and IP addresses) and to whom it is being sent (your audience members).

If you’re a visual learner, there’s a nice infographic of the email delivery process by Focus.com here.

But that’s just a small piece of the mystery. Let’s dig in …

So you’ve got a message that’s ready to be sent, and it’s up to the mailer (MTA) to make sure it goes to the right place. First, the MTA establishes a connection to the MX record, found in the DNS for the domain to which you’re sending. (For example, you might be sending to domains like gmail.com, hotmail.com or companyname.com.) A domain’s DNS is a one-stop location that other machines use to communicate with the domain’s various servers, and the MX record is there to process any incoming mail.

If the connection is unsuccessful, there may be a permanent issue (like the domain not existing) or a temporary one (bad connection, Internet connection issues) that may be resolved when Emma reattempts delivery. (Emma typically makes up to four delivery attempts, if the first connection is unsuccessful.)

If the connection is successful, it’s time to send that email. This is done using a process called SMTP (Simple Mail Transfer Protocol). Traditional SMTP transactions have these main parts:

1. HELO or EHLO (an extended SMTP command) identifies the sending server and the receiving server.
2. MAIL FROM identifies the email’s sender (your RSVP address).
3. RCPT TO identifies the email address you’re trying to reach. There’s one of these for every address you send to.
4. DATA is where you transfer the actual information — HTML, text, images — you’re trying to convey via email.

Usually, this entire transaction goes by pretty quickly (in a matter of seconds or minutes), but there are some reasons why it may be slowed. Some servers take longer than others to respond to the different parts of SMTP, usually by design to allow time to check the information being passed their way, and that can result in a timeout on the connection (and eventually a soft bounce, though that is rare). When they do occur, the Emma delivery team has the ability to alter our expectations for connections to that domain so that we wait the appropriate amount of time for responses. Of course, there are other common issues like unknown users, full mailboxes and potential authorization failures when SPF or Sender ID records are present but are improperly configured or invalid (speaking of which, now might be a good time to have your IT folks update your SPF record). Once the SMTP transaction is complete, and the message has either been accepted or denied, your email is ready to be delivered to the recipient the next time they access their email from a computer, phone, tablet, etc.

What you can do

Now, just because an email is successfully delivered doesn’t guarantee it ends up in the recipient’s inbox. To ensure the email lands in the inbox, you should follow these best practices:

• Ask your recipients to add your RSVP address to their address book or trusted sender list.
• Have your IT folks update your organization’s Sender Policy Framework (SPF) record.
• Avoid words and phrases that can be caught in spam filters.
• Don’t let formatting changes outshine your campaign content.

There you have it: the wandering path of an email. It seems complicated, I know, but the powerful machines that handle email delivery are notoriously good at completing all of the necessary steps. Still, it’s certainly not cheating to have a little guidance, and Emma’s here to help you create and send solid campaigns and to offer explanations when delivery issues arise.

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Want to read more about email delivery? Check out Mary’s post about list hygiene or Claire’s post about the differences between permissions and opt-ins.