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The journey of your emails this Christmas

How does the email journey work from a technical perspective? How exactly does a message get from the sender to the receiver? Let’s find out.

Hermes on Santa's sleigh



Christmas is just around the corner - at least for the email marketer - and the time to think about your Christmas campaigns is now. Sending the perfect email to the right contacts at the right time is hard, and even harder if you don’t understand how all of your fantastic Christmas campaigns make their way into your recipients’ inboxes. So, how does the email journey work from a technical perspective? How exactly does a message get from the sender to the receiver? Well, let’s find out.

The journey to the inbox

OK, so let’s start with something obvious. Before you can send your beautiful Christmas campaigns to your subscribers, you need to create them. Groundbreaking, huh? Lucky for you, many email service providers (ESP), like Mailjet, offer editors to make designing an email easier.

So after spending some time looking up the funniest gifs and festive images, playing around with the colors and drafting the best content, your campaign is ready, its design is optimized for deliverability and it really looks beautiful. Great job! Now is the time to press the “Send” button. Scary, right? Well, wait till you see all that’s happening behind the scenes.

Step 1: Getting ready for departure

You just pressed “Send” - your work is done. Now it’s the ESP’s turn to get to work. During this first step, the ESP (Mailjet, that is) prepares your Christmas campaign for sending by completing a series of steps. First, if you have used any personalization in your email, like using dynamic subject lines that include your contact’s first name or other demographical data, this information is applied. The email is also provided with a digital signature so the receiving server can verify the domain (DKIM). Then, the ESP converts your email into two sections: the header and the body

Before your email can leave Mailjet, it has to go through various processes where it will be formatted, checked and passed. But what is checked, specifically? Well, pretty much everything. Mailjet’s MTA (Mail Transfer Agent, the software that transfers emails from one computer to another) looks out for potential spam or malware, and assesses everything from the length of your message to the words and characters used.

Finally, the ESP adjusts the delivery speed to fit each ISP’s own speed. The ISP is the Internet Service Provider you’re trying to send your emails to. For example, Gmail, Hotmail or Yahoo! Some ISPs accept larger volumes of emails in a short time span than others, so the ESPs send your campaigns at different speeds, breaking the total emails you want to send into different chunks to optimize your sending. 

Step 2: Knocking on the ISP’s door

Once your email campaign is approved by your ESP (Mailjet, of course), your email is ready to step outside, walk into the wild, unknown territory that is the digital spectrum and make its way to the receiver. Your ESPs MTA (reminder: that is, the software Mailjet uses to transfer your email to another computer) now checks if the destination you’re trying to send to exists, by looking at the Domain Name System (DNS). If everything is correct, your ESPs MTA sends your email campaign to the MTA of your contact’s email server.

The email has been sent to the recipient’s mail server, your subscriber’s ISP. But before it is even accepted, the ISP’s MTA checks some of the information coming from the ESP. One of the main things ISPs investigate is your sender reputation. As with everything in life, reputation determines how successful you’ll be with your email strategy. Think of it as going to a club: if you’ve caused trouble there before, got into a fight or not paid your bill, you’re not going to get in. Same will happen if you’re not following the dress code, for example.

It’s the same with emails. A bad sender reputation will negatively affect your deliverability (that is, your ability to successfully deliver emails to the recipient’s inbox). The ISPs you’re trying to send to may block your email, so having a positive reputation is key to mastering email deliverability. You might even get blacklisted, which means you’ve been labelled as a spammer and your campaigns might have a harder time reaching the inbox.

Aside from your reputation, ISPs check a number of other elements to establish whether they should let your emails in or not. They try to figure out if the ESP is known and if the sender authentication (SPF and DKIM) is in order. ISPs also look into the metadata, format and structure of the email to ensure they are correct (the HTML code) and check whether the recipient inbox exists and isn’t full.

If your email doesn’t pass these checks, or if the email address you’re trying to reach simply doesn't exist, it gets bounced. A hard bounce would occur if the ISP has determined the email address you're trying to reach does not exist or is no longer active. If it fails any other checks, then it results in a soft bounce. And that’s not it. Depending on what checks your email has actually failed, the kind of soft bounce you get could be different. It might get a temporary bounce telling you to re-attempt the message because they might be willing to deliver it later. Or your Christmas campaign might get rejected (and your future sendings too), which would mean the ISP is not willing to let your emails through until you improve your practices and your reputation. 

Step 3: Landing safely

But your campaign is awesome and it has passed all the checks and convinced the ISP to finally open its doors. Yay!

Now it’s the ISPs turn to look into the actual email. Basically, the ISP will make the content go through some internal spam filters and assess your sender reputation against its own reputation list.

When an email fails these requirements, it will be sent straight to the Mordor of the emailing world, the junk folder. If you’re lucky, your campaign will be spotted there, but we wouldn’t put our money on this. And even if it does get noticed, having your emails land in the spam folder doesn’t give the best first impression.

If your email manages to pass this very last obstacle, then it will be allowed to land safely in the inbox, along with many other emails fighting for your contact’s attention. Some ISPs, like Gmail, even have different folders within their inbox. Now it is up to the title, design and content of your email to shine and really grab the reader's attention.

The inbox folders in Gmail

At last, the journey of your email is finally over. Yeah, we know, looking back, Santa’s journey around the globe to deliver the Christmas presents pales in comparison. But all of these intermediate steps and security measures are necessary to ensure that no harmful messages reach the inbox. And actually, what looks like a long and eventful journey could really just be a matter of seconds.

How much did you know about the journey of your emails through the Internet? Tell us all about it or tweet us your questions using the hashtag #MailjetDelivers.

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