How to Target the Right People with Segmentation via Mailjet’s API

Do you want to increase your email open rates, boost your click rates, and decrease your unsubscribe rates? Of course, you do! Well, the best way to achieve that is to stop sending the same email to all of your subscribers. We know you know that every one of your subscribers is unique, so why would you send the same email to all of them? Instead, start segmenting your email list and send the right emails to the right people. Keep reading to find out some segmentation ideas, and we’ll also cover how to use segmentation with Mailjet’s API.

What is Segmentation

To understand why you need to segment your list, we’re going to need to cover the basics first – namely what exactly segmentation is. Information such as age, gender, location, and interests can provide a lot of insight into your customers’ needs and help you with segmenting your list in the right way. Segmentation is actually the action of dividing your contact list into parts. Then, you can create personalized and relevant emails for each segment.

The most important thing to take into consideration is why this contact joined your list, so you can send them the right content. You wouldn’t send a promotional email for Star Trek items to a Star Wars fan, right? The point is to send them the content they would find interesting and relevant, and this way you can increase your open and click rates while worrying less about the unsubscribe rate. Consumers now actually expect personalized emails and segmentation is one of the easiest ways to deliver on that expectation.


Now that we know the basics of segmentation, let’s dig deeper into the advantages of using it.

Why you need Segmentation

Segmentation is a highly effective email personalization technique. By dividing your large list into different groups, you can send more targeted emails and focus on sending emails that build trust.

Segmentation is a simple but powerful mechanism that can boost your engagement and profits. To segment correctly, you need to think in groups and find something in common for each group. And if it is something beyond the obvious separation between men and women, you can show your customers that you know them. The segments can be as large or as small as you want, but in most cases, the smaller they are, the more likely it is that the information you send will be relevant for the recipient. Without email segmentation, it’s difficult to engage your subscribers and improve your conversion rate.

Some ideas for segmenting your lists

Once you have collected the necessary data, you now need to decide what the best way to group your subscribers into segments is. You can create segments based on age, similar purchase histories, interests, and different traits relevant to your brand to send targeted emails. Once you start brainstorming segmentation criteria, the possibilities are almost endless. You can use all the data you’ve collected so you can create the perfect email for each segment. Here are some ideas for segmentation:


However large or small your target market might be, you can use geography to segment your email list. You can create a special email category for people in a particular city or country if your business has a presence multiple ones.


You can get detailed information about subscribers’ personal interests by creating user profiles on your website, or using an email subscription center, or even your opt-in. You can ask them anything that can help you send them more relevant information and offer them the right products.

Browsing Behavior

If you are keeping track of website behavior, this is one of the simplest ways to create the right segments. With browsing behavior, you will know what each customer is browsing and what they are looking for.


Knowing the general age range of the people on your list can be helpful with removing those not in your target audience, or to adjust the messaging of your email communications to better suit that demographic.


This may be pretty basic, but it is still one of the best segmentations that you can use. Offering the right range of products to women and men is something that can be accomplished so easily, and still, be so efficient.

Purchase History/Purchase Behavior

Segmenting by past purchases is another simple way to optimize your email targeting. You can always offer products that are similar to the one that the customer already bought. Or, if a customer bought something that requires replacement, refilling, or renewal, you can send out targeted emails based on their needs.

You can even consider some clients as VIPs after a certain number of purchases. You can add a dedicated section in your email specifically for them and create a segment to target them.

Email behavior

Open rates and click rates are metrics that everybody should be checking and collecting information on. They are the easiest way to know which contacts are] active, and which ones are no longer engaging. You can then create a specialized campaign designed at re-engaging your inactive subscribers or offer the active ones the latest news.


If you are planning on making surveys, there’s no doubt you’re planning on using the results in the best ways, and we’re positive one of them is for sure segmentation. You can build emails for the different segments that you created depending on the feedback you received.

You can segment based on everything you can think of that’s relevant to you and your brand. There are no limitations.

Now that you have some ideas, let’s explore actually creating a segment with Mailjet’s API.

How to create a segment with Mailjet’s API

Creating your segments will be so easy and it can be done with just a few lines of code. We’re going to walk you through an example where we will create a segment for all men from London that are interested in Star Trek, so we can offer them our new Star Trek-inspired male collection.


Our /contactfilter resource allows you to create segmentation formulas like the one below:

curl -s \
        -X POST \
           -H 'Content-Type: application/json' \
           -d '{
                "Description":"Only men from London that are interested in Star Trek",
                "Expression": "((gender=\"men\") AND (city=\"London\") AND (interest=\"Star Trek\"))"
                "Name":"Star Trek new collection London"

As you can see you can add a description, expression, and name for each segment. Since the name and the description is something really obvious, we will focus a little more on the expression part. This is where you are actually saying who will receive the message. You can have simple expressions with only one condition or complex ones with more conditions connected with “AND” and “OR” operators.

You can find all the operators that are available for comparing the properties here. You will need to keep in mind that not all of them are supported by our interface. Because of this, some segments created via the API may not be recognized as valid in the app. However, you will still be able to use them in your campaigns. You can use any of these operators to create the perfect segment for your needs.

Another thing that you will need to know is that you can only apply one segment to a campaign. This is why if you need to make sure that your segment is perfect before going to the next step.

When the segment is ready, it’s time to apply into your campaign! For this, you will need the Segment ID. You can find the payload you received as a response for the segment you created, and it will look a little something like this:

     "Count": 1,
     "Data": [
               "Description": "Only men from London that are interested in Star Trek",
               "Expression": "((gender=\"men\") AND (city=\"London\") AND (interest=\"Star Trek\"))",
               "ID": "123456",
               "Name": "Star Trek new collection London",
               "Status": "unused"
    "Total": 1

Take note of this ID and keep it safe because you will need it for the next step.

Sending to segment with Mailjet’s API

The segment should be applied to a campaign draft and you will also need the list that you want to use. Two more IDs will be needed for this – the one from the campaign draft and the one from the list. Once you have those IDs, the rest is easy. You’ll simply have to execute the code below and the rest is done:

curl -s \
       -X POST \
            -H 'Content-Type: application/json' \
            -d '{
                 "Subject":"Greetings from Mailjet",
                 "Title":"Friday newsletter",

Summing up

Now you are ready to send the campaign (once you’ve made it pretty, of course). The last thing you will have to do is publish the draft and send it as campaign when you’re happy with the content. All the steps for how to do so can be found in our documentation.

If you want to find out how you can use segmentation in an advanced way with our Passport tool you can check those two articles for marketing and transactional templates.

What Is the Return-Path and Why You Need to Customize It?

Have you ever heard of a return-path? If you haven’t, maybe you are missing one thing that you can do to help your deliverability. The return-path is the one that will help you manage your bounces and clean your list. Let’s check it out in details.

What is a Return-Path?

We’ll start with the purely technical return-path explanation provided in the standard RFC documentation and then break it down and explain it in a more understandable language.

The return-path header (return-path header, in English) is an SMTP email source address (SMTP MAIL FROM, in English) used to process the bounces that occur in your emails.

It can also be called reverse path, sender, sender, MAIL DE, 5321-DE, sender, De_ and Errors a. This address receives information on all bounces. As much as we hate them, rebounds still happen and we must be aware of that. This can be tons of help for your your deliverability.

So this means that once the email is sent, the return-path is added to preserve the value of the SMTP MAIL FROM command. So, it is the mailbox provider (for example Mailjet, Google, Hotmail, Yahoo) that adds the return-path header.

When you look at the full header of your message (we know that you don’t usually do that, but you can try now just to see what we are talking about), you will see the return-path header somewhere at the top. In most cases it’s just above the Received header, which shows the public IP where the mail was sent from (in our case this would some of Mailjet’s IPs).

It is important to know that there should only be one return-path header. In the case there are more, this would indicate that something is wrong with the SMTP configuration and you need to dig deeper to check it.

Up until now, everything sounds so strange, right? Maybe knowing the main purpose of the return-path will enlighten you a bit.

What is the return-path for?

Return-path is used to process bounces. As an email service provider, it is a good idea to have a generic address that is handling those bounces. This should be an email that you will have access to, and therefore an email with your domain. Do you see where we’re going now?

Return-path is added once the email is sent, to preserve the value of the SMTP command MAIL FROM. Therefore, it is the email provider (e.g. Mailjet, Google, Hotmail, Yahoo) that adds the return-path header.

The return-path header must be present in all emails to track bounces. If the return-path header is not present and a bounce occurs, the email servers will be confused and will not know where to send the bounce notification. This means that you will not know the existence of the bounce, you will not be able to remove that address from your list and you will continue to send to that address, which can negatively affect your sender score.

In Mailjet, all emails pointing to an address in Mailjet’s SMTP environment will have a return-path address with a Mailjet domain. This means that everyone who receives your emails will be able to see the return-path that you use and that you are a Mailjet customer. For some people, this is no problem. However, if you wish you can customize your return path using a CNAME record.

Why should you customize your return-path?

The reason for customizing your return-path has to do with email authentication processes, or how the recipient’s server determines which emails to let through and which ones it rejects.

DMARC is an email validation system created to detect and prevent phishing. One of the many tasks the DMARC system performs is to check the concordance between the sender’s name and your return-path name.

With the increase in phishing attacks, ISPs have been trying to protect their reputation. Even trusted email providers are subjected to exhaustive controls.

There are many factors that can cause problems with deliverability, but one of them has an easy solution: clean up your email header and customize your return path. Each server has a different way of interpreting email headers to establish authenticity, but the more systematic the signals in your messages, the better.

It makes sense that the DE address and the return-path address have the same domain, doesn’t it? Many servers will reject an email claiming to come from a certain address if the message is not sent by a server that usually manages that address.

With Mailjet you can customize the return path to ensure that no one gets your reputation compromised through a CNAME record. To understand how it works, we must first see what CNAME is.

What is CNAME?

CNAME is the abbreviation for Canonical Name. CNAME records can be used to alias for a name. Any system hosting a site must have an IP address in order to be connected to the World Wide Web. The DNS resolves the name of your site to its IP address, although sometimes several names resolve it in the same IP address , and this is where the CNAME is useful.

For example, if you own and that points to the same site or application and are hosted on the same server, it would be very useful to create the following to avoid keeping two different records:

  • An A record for pointing to the server IP address;
  • A CNAME record for pointing to;


Then you will have, which points to the IP address of the server, and points to the same IP address of the server ( If it is necessary to modify the IP address, you only need to update it in one place since it will be replicated in the other.

However, the CNAME has some restrictions.

  • You should always point to another domain name and never directly to an IP address.
  • It cannot coexist with another record for the same name. You cannot have a CNAME and TXT record for
  • You can point to another CNAME record, although generally this setting is not recommended for performance reasons. If applicable, the CNAME record should aim as much as possible at the target name to avoid unnecessary performance demands.
  • You cannot put a CNAME record at the root domain level because the root domain is the Start Of Authority (SOA) of the DNS that must point to an IP address.
  • MX and NS records should never point to a CNAME alias.

A surprising novelty is that with the latest generation of DNS technology, the same CNAME record will be able to redirect to one of several names based on dynamic parameters. This will make it even easier to manage CNAME records.

A and CNAME records are sometimes confused, but they are two different and common ways of assigning a hostname to one or more IP addresses. There are important differences between these two records that need to be taken into account. Record A points to a specific IP (you want to point to server and the CNAME record to point to another name instead of an IP ( points to

Think of the CNAME record as an alias for the destination name that inherits its entire resolution string.

Some common uses of CNAME records are:

  • Provide a separate hostname for specific network services. Common examples are email or FTP that points that hostname to the root domain.
  • Many people use subdomains to manage their different services or clients linked to the primary domain (for example,, and CNAME record to point to the client’s domain (
  • Register the same domain in several countries and have the country versions point to the main domain “.com”.
  • Point from several websites owned by the same organization to the main website.

How you can customize your return-path

Now that we know more about the CNAME record, let’s see how you need to configure it to be able to customize your return-path with Mailjet. We’ll use the first of the common examples: you use a CNAME record to have your own domain point to our domain in the return-path address.

The default return-path Mailjet uses is “”. Since we must receive the bounce events, you cannot change it completely, because if you do we will not be able to receive the events.

Setting up the CNAME

To customize your return-path, you’ll need to do three simple steps: create a subdomain, create the CNAME record in your DNS zone, and contact us to activate the redirection.

Step 1

Create a subdomain in your main domain using the prefix “bnc3”. For example, with a main domain, you will have to create a subdomain

Step 2

You must access your DNS zone and create a CNAME record that looks like this: IN CNAME

This will mean that your domain will now point to Therefore, everyone will see in the email header, but it will actually point to our and we will continue to receive bounce events and update your statistics.

Step 3

The final step would be to get in touch with us. To do this, you can open a ticket with our support team and provide us with the following information so that we can activate your personalized return route:

  1. The API key you want to activate the return-path.
  2. The CNAME record you configured: the screenshot or text version of the record will be perfect.

Please note that you can only have one active return-path per API key.

Once we have this information, we will do the necessary and our agents will get back to you with the good news that everything is ready. And there you go – you have your customized return-path.


Deliverability is very important to every sender and in this article, we have learned one more thing that can help you make it easier. The return-path is important for email providers to know where to send the bounces and where to deal with them. We’ve also learned why it’s best to customize it, what the CNAME record is, and how it works.

For more useful articles, don’t forget to follow us on Twitter and Facebook.

Using the Scrum Framework in your Email Marketing Teams

Let’s be honest with ourselves a little bit here. Sending email campaigns can sometimes feel like one of two fun, but strangely aggressive, children’s games.

Whack-a-mole, and pin the tail on the donkey.

Whack-A-Mole Gif

Sometimes it can feel like we are just trying to keep up. We know we need to send a daily newsletter, or a new campaign promoting a sale, or tweak an old transactional email template.

We also need to keep up with the times, incorporating personalization, segmentation, and maybe even the odd piece of interactive content into our emails. Those moles keep popping up, and we simply try our best to whack them down.

Other times, we’re blindly sending a campaign, choosing a subject line, embedding an image seemingly on a whim, hoping for the best, thinking ”maybe this time I actually pinned the tail on the donkey”.

I imagine you’ve felt this way once or twice in your email career. Even when we have a clear plan, strategy, and roadmap to get somewhere, we can still feel lost in the dark.

As you can imagine, these problems are not unique to email teams. They’re actually pretty standard across any project involving consistent shipping like factories, software releases, and advertising just to name a few.

There are a whole host of ways to approach a problem like this, some of which we’ve covered on other blogs about email teams and workflows. But one approach that has historically worked very well is the Scrum Framework for Email Teams.

What is Scrum?

Scrum is a framework for teams to work together on iterative projects in a more effective way.

Perfected over the last decade or so by software development, a Scrum team brings together a cross-functional group of people to abandon their job titles, and within short segments, release products (or campaigns) quickly.

These segments, referred to as sprints, can last anywhere between a couple of days to a month. The length really doesn’t matter so long as the end result is well defined, achievable, and can help inform future “sprints”.

Rather than approaching projects with a waterfall methodology where projects start with a clear plan that is stuck to from point A to Z, Scrum uses sprints to optimize for changes. Whether it’s a change in the scope of the project, a change in the data we’ve collected about our end-user or audience, or a change in our team.

A Scrum team, consisting of a project owner, developer team (or creator team), and Scrum Master, cycle through phases of sprint planning, daily stand-up meetings, development, and release.

If the larger project is to release an app, a sprint could be as simple as building the landing page. If the larger project is launching a new daily newsletter, a sprint could be as simple as building or refining the contact database.

If you want to dig more into what Scrum is and how it works, our friends at Atlassian do a great job for you here.

How does Scrum apply to email teams?

The nature of Scrum is bringing together cross-functional teams to release complex projects in an iterative way.

When you think about some of the modern email campaigns today that involve beautiful design, excellent copywriting, personalization, and interactive content, you begin to see not only all the work, but also all the people that go into email campaigns.

Nike Interactive gif

There’s copywriters, designers, motion graphics designers, CRM specialists, data engineers, developers, a deliverability team, lead/contact generation team, and sometimes even more. Let alone the teams that also rely on external agencies and third-party providers. A Litmus survey in 2018 found that on average there are 8 people that go into an email campaign.

The problem is especially compounded by the fact that these individuals often come from 3 or more different departments, and email is likely not their only task. Rather than operating in silos, one great benefit of Scrum is the ability to not only tear down silos, but by definition tear down job titles.

In Scrum, you check your job title at the door and simply become a part of the “Developer” or “Creator” team of a sprint.

Scrum is particularly compelling for email teams because of the iterative and data-centric nature of email. Depending on your company, you could be sending out millions of emails every day, capturing data and reimplementing on an on-going basis.

Rather than breaking email down into large chunks that go through changes maybe once per quarter, email teams can be using the lessons they’ve learned in the creation process, and in the data from each campaign, to drive decisions on a daily or at least weekly basis. A Scum approach allows for this.

The People on a Scrum Email Team

There are three primary roles within a Scrum Team (at least as defined by the original Scrum approach…but this can be flexible):

  1. Project Owner
  2. Creator Team (or Developer Team)
  3. Scrum master

How can this apply to your email team?

Project Owner

A project owner’s main responsibility is to maximize the value of the Scrum team and oversee the project backlog of tasks, ideas, and campaigns. They clearly define and prioritize what the team can be working on during sprints, and has an eye on finding those sprints that can have the most impact on the business for the least cost.

This will likely vary across your teams, but an Email Marketing Manager or Email Loyalty Manager fits this role well. Sometimes it could be a Digital Marketing Manager or VP of Marketing who has their sights set, not only email, but also how email also fits into the larger scope. Regardless, this is one person. One very important person.

Creator Team

The Creator Team (or developer team in software development parlance) includes people who produce a “releasable increment of the product”. Or, in other words – a finished sprint. As you can imagine, this creator team can be quite fluid depending on the sprint. This team can consist of any configuration of email marketers, copywriters, designers, CRM specialists, data engineers, and on and on. If the sprint goal is to create a new template, it more likely involves designers and copywriters, compared to a sprint that is trying to create a new segment.

Scrum Master

A Scrum Master serves the role of advisor on the project. They help everyone understand and put into practice the Scrum framework through advice, coaching, and ensuring the process is being followed properly. When everyone’s head is down on their work, it’s easy to forget or deprioritize important elements like daily scrums, prioritizing sprint items, and ensuring a deliverable’s scope doesn’t evolve.

A Scrum Master often contributes to the Creator team as well, so this role can be filled by the Email Marketing Manager, a designer or someone else on the Creator team. Sometimes, however, a Scrum Master is outside the Creator team and serves this role for multiple different teams, such as VP Marketing or Digital Marketing Manager.

Creating an Email Campaign Using Scrum

To help illustrate, let’s look at an example of where you can apply Scrum to email. And where else could be better than the peak of email every year – Black Friday. In a traditional workflow, perhaps the waterfall methodology, you would:

  • Define the project: determine, perhaps 2-3 months in advance the campaign you want to send on Black Friday to drive the most clicks or traffic to your store.
  • Build: you would then follow your plan or Gantt chart to a T, ensuring that you first create a template, then add copy, then add segments, and so forth.
  • List: Now, with Black Friday just around the corner and your series of campaigns set up, you would then send a few tests to make sure they look good in all inboxes.
  • Send: Now, you trigger your campaigns and hope for the best.

This approach is solid, and probably the one you are pretty familiar with. Plan a campaign, build it, send it, move on.

A Scrum-based approach, however, breaks up this large plan (or this large gamble) into smaller component parts. It lets you test the components along the way contributing to a more validated, and more informed series of campaigns come Black Friday.

Sephora Black Friday scrum email

Let’s take a look.

Project Backlog

The project backlog is essentially your master to-do list. Within this list are the tasks, ideas, and enhancements for the larger project.

For Black Friday, this could include things like:

    • Create new templates for each email
    • Integrate your user data into your ESP
    • Create a dynamic recommendation section to ensure sale items are personalized
    • Write copy to promote each sale item
    • And so on.


Sprint Backlog

A sprint backlog is the subset of this list that the Project Owner (with input from all stakeholders) has decided should be the next priority. They decide on a short time-bound “sprint” to accomplish these tasks. Perhaps, for Black Friday, the first priority is to ensure that you have well-defined segments ready for the Black Friday campaign.

So, in this backlog, you could include tasks like creating segments based on past buyer behavior. Rather than waiting until Black Friday to refine and define these segments, Scrum allows you to create your segment months ahead of time, test it, and using the data you get back you can also improve the granularity of these segments.

Daily Scrums

Daily scrums, or stand-up-meetings, are an important part of Scrum. They are the daily meetings that your team has to go over: (1) what have you since the last stand up, (2) what you are working on today, and (3) what are you facing to get your task done. This breeds accountability, collaboration, and consistent progress throughout the sprint.


Increments are essentially the “releases” of each sprint. The delivery you send out to the world. When developing an app, this could be a new feature release. In email, this could be sending a new campaign or publishing a new template.

Our sprint above could result in building new segments and sending a new promotion. We can now use that data to continually improve our segmentation strategy leading up to Black Friday.

Sprint Review

After the release of your increment, or campaign, a sprint review (or sprint retrospect) reviews how the previous sprint has gone. What did you accomplish, what problems did you encounter, and what new information did you gain that you can then use for future sprints?

Our segmentation sprint ahead of Black Friday could have revealed new interesting user data such as designs and templates that could work for one segment over to another. Perhaps you learned that certain segments respond to “sale” messaging differently. You can use this information for future sprints and for the ultimate Black Friday campaign.

So Scrum is for anyone and everyone?

No, of course not. Scrum is a set of guiding principles that can help you define and deliver your projects in a more consistent, evolving nature. Is that for everyone? No.

Is it for every email team? No, not necessarily. Some teams may have less of a need to create, test, and adapt. Some teams may be small enough that they don’t need to consider how to bring cross-functional teams together.

But, as email teams grow and become more cross-functional (especially in enterprise organizations), then we need to reconsider the linear approach to how your team builds and sends emails. Perhaps an iterative approach is best for you.

So what’s next? We have three recommendations for you:

    1. Identify who’s on your team, including those who don’t contribute daily
    2. Find projects that have a big goal and a long time frame. Make small bets, not big gambles
    3. Turn one email project into a scrum email project (new template, new campaign, etc.)

Have any scrum projects you’re dying to tell us about? You can find us on Twitter and Facebook.

Email Marketing Best Practices to Improve Your Performance

No matter what you’re doing, you want to give it your best, right? With email marketing, giving it your all will result in higher customer engagement, which means more opens, clicks, and maybe even more conversions. We made a list of email marketing best practices to help you focus your efforts to where it counts.

Top 12 email marketing best practices

Following guidelines might not be the most fun thing in the world. You might think it puts a bit of a limit on your creativity. But these guidelines are going to let you be as creative as you want, and see the results you want as well. So let’s get into it!

Best Practice #1: Double Opt In

So someone has just signed up for your emailing list…why would you want to send an email to make sure they want to be on that list? Because double-opt in can reduce your spam complaints right down to well within acceptable levels.

A double-opt-in is an email that is sent out to your new subscriber asking them to confirm their subscription by clicking a button within the email. Mailjet lets you build your double-opt in email and helps you send them out as soon as you have a new subscriber.

You’ll want to keep these emails on the shorter side. Make sure you put your CTA, in this case the “Confirm Subscription” button, at the top of the fold. It’s the main purpose of this email, so make it stand out! But we’ll cover this in more detail later. As for the rest of the email? Let your customer know what to expect, and why subscribing was the best decision they made all day.

Pottermore Opt-In Email

Best Practice #2: Test it out

Do you taste a little bit of the food you’re cooking before you serve it to your guests, making sure it’s as delicious as you want it to be? Email marketing functions on the same principal: test before serving!

Testing out your emails before you press send will give you the chance to make sure everything is in working order. We all know the feeling of pressing send, and right as starts its journey to your contacts’ in boxes, you spot a typo. And your stomach drops 😧 Testing is going to help you avoid this feeling.

But don’t just check for typos, also give the links a click to make sure they go where you want, check to see that the photos are rendering correctly, and ensure that you’re not missing any data. The list goes on and on.

Here’s a quick checklist of things to test before sending your email marketing campaign:

  • Spelling and typos
  • Links and CTAs
  • Images show up correctly
  • Looks great on both mobile and desktop
  • You chose the right contact list
  • Sending from the correct address

It’s also a good idea to send it to at least one other member of your team. A fresh pair of eyes that haven’t been staring at the same email all day will be able to catch details that might have slipped past you.

At Mailjet, you can preview how your emails will appear on mobile and computers, as well as send out a test email to anyone you want before you send it out to your entire contact list.

Best Practice #3: Keep the spam in the can

Yeah, we know… this one may seem self-explanatory, but you may be doing some spammy things without realizing it. We’ve got a full blog post on how to avoid email spam filters you should definitely it check out, but we’ve summarized some of the big ‘no-goes’ below.

The biggest and most obvious one is purchasing lists – just don’t do it. It is better to build up a contact list that opted-in to receiving your emails so that you have engaged customers that won’t mark your emails as spam.

Next up, make sure the content of your email is relevant. This may seem obvious, but your customers signed up for your emails for a reason and you want to make sure you’re delivering.

Your subject line is also something to keep in mind; practices, like writing it in ALL CAPS or throwing in far too many emojis🤣🍔🎧💖🔥, can make you look spammy in the inbox. There are also some words that you really don’t want to use if you don’t want to sound the spam alarm.

Gif of Spam in a can

Best Practice #4: Clean your list

It may seem tedious, but routinely cleaning your contact list is another important key to achieving great deliverability.

Cleaning your list means removing bounces, blocks, unsubscribes and inactive contacts from your list so you can avoid being marked as spam by frustrated customers that do not want to receive your awesome emails anymore (they must be crazy 😑).

Beta List Unsubscribe email

Speaking of unsubscribes, it’s important that you add an unsubscribe link in every one of your emails, and make sure it is visible! We know that you put in a lot of work to add them to your contact list, and this may seem contradictory to your goal, but we promise it’s for your own good.

Customers that can’t find your unsubscribe link may resort to marking you as spam if they can’t find any other way, and rack up enough of those and you won’t be able to reach any of your contacts, including the ones that love your emails. Additionally, an unsubscribe link is mandatory to remain GDPR compliant, which is something we take very seriously here at Mailjet.

Best Practice #5: On the subject of subject lines

As mentioned before, you don’t want your subject line to look spammy – but there is a lot more to them than that. Ideally, your subject line will be short and sweet, but engaging and enticing.

You’ll want to keep it somewhere between 30-50 characters, keep it consistent with your brand image, describe what your email is about, and make it all but impossible not to click on. Tall order, huh?

There are many different ways to make your subject line stand out in the inbox. Just to give you a few ideas, you can add a couple emojis (being careful not to overdo it 👀), add the recipient’s name to give it a personal touch, or include action verbs that call on them to interact. If it matches your brand image, you can even keep part or all of your subject line the same every time so your subscribers recognize your email when they get it.

Regardless of which tactic you choose, it’s a good idea to test it out to find out what works best. A/B Testing can help you out with this. You can test multiple different subject lines by sending each one to a small group of contacts, and then the best performing one will be sent out to the remainder of your contacts.

Regularly testing your subject lines will help you find what works with your contact lists and improve your open rates.

Best Practice #6: Simplicity is key

You love your brand, and you want to share as much of it as you can with your subscribers, but you might want to hold back just a little bit. Cluttering your emails with as much content as you can actually be counterproductive to your goal of engaging your customer.

Think of it this way: have you ever clicked into a website and just suddenly been bombarded with images, text, and interactives? You had no idea where to start, so you just didn’t start at all, opting instead to click out and find a new website that didn’t assault your eyeballs. Your email should have enough content to be worthwhile interacting with, but not so much that there is no focus to it.

Uber Simple Email

Best Practice #7: CTAs

CTAs, or call-to-actions, are most likely going to be the focus of your email. It is what you hope your subscriber clicks on when they’re scrolling through. Because of its importance, you’ll want it to stand out from the rest of the content.

“How do I do that?” you may be asking. Color, copy, design and placement all play a role in this.

The color should fit your brand image, and make it stand out from the background of the email. The copy is both what is written on the button, as well as the text of the email that surrounds it. Again, it should match your brand image, but it’s also a good idea to get a little creative about it. Average, run-of-the-mill buttons like “click here” and “read more” aren’t exactly eye-catching.

When paired with the design of the button, like shape and size, you could really boost your clicks.

When you’re placing your CTAs, there are some things you’ll want to keep in mind. First off, you’ll want one right when the email is opened, with no scrolling required. With this in mind, you’ll also want one at the bottom, particularly if your email is a little on the long side. When your reader gets to the bottom, you won’t want to have to make them scroll back up to click on your button.

Lastly, don’t go overboard! You’ll have to find a good balance between content, images, and CTAs. Too many might muddle the goal of your email, whether it’s to sell products, get people back on your website, or something else.

Best Practice #8: Adding ‘alt text’

‘Alt text’ is like Casper the Friendly Ghost. Invisible to most, but helpful when you need it! Ok, so the comparison might be a little off, but alt text does function just like that.

Casper the friendly ghost gif

You’ve taken lots of time and effort to design an email you know your subscriber is going to love, images and all. But then, when your customer opens the email in their inbox, the images don’t load and there’s just a big empty spot. Some reasons why your images might not be loading are the email client might automatically block images, or problems converting between email formats. This is where ‘alt text’ comes in to save the day.

When the image doesn’t load, your ‘alt text’ will appear in the empty spot, giving your readers an idea of where they’re supposed to click, instead of leaving them in the dark.

Alt-text in an email

Best Practice #9: Keep your branding consistent

Your brand’s image is important, and you want your email marketing to keep that image consistent. The colors, copy, design and tone should all be kept in mind because you want your customers to recognize your emails week after week.

If you’re working as part of a team, it can be hard to keep branding consistent with so many cooks in the kitchen, so to speak. That’s why at Mailjet, we made it possible to lock sections so that those will remain consistent from one email to the next. You can lock the header and footer, and let your team take creative liberty over all the rest!

Mailjet's locked sections

Best Practice #10: Make your emails more relevant

We all know humans are better than robots (at least you do if you’ve seen Blade Runner, The Terminator, Ex Machina, Resident Evil…I could go on). Emails with a bit of personalization in the subject line, like adding their name, for example, have a higher rate of being opened.

The subject line isn’t the only place where you can add a personal touch. Beyond even just adding it in the text of the email, you can also personalize by your customer’s behavior. This is where segmentation comes in.

Segment your customers by age, location, or even favorite products, and then build emails that are specifically made with these groups in mind. Of course, be careful not to get too creepy with it (maybe stay away from subject lines like “Talia, we know what you want and here it is” or something like that…creepy ☹️).

Best Practice #11: Make use of those statistics

So you sent off your email, and now you’re done, right? Nope. This is where email statistics come in, and they’re what’s going to help you make the next email you send out even better.

After you send out your email, review the stats you have at the end of the day, the next day, the following week, even over the course of the next few weeks! A lot can be learned from your email statistics about what your customers like, and maybe even more importantly, what they don’t like.

Mailjet statistics

Stats like open rates, click rates and A/B test results are just the tip of the iceberg. Reviewing your statistics routinely, and then creating and narrowing down email hypothesis that you’ve come up with is a sure way to improve your engagement rate.

And besides, look at it this way: coming up with all those hypotheses and giving them a test will make you feel a little bit like a scientist. An email marketing scientist. 🤓

Best Practice #12: Request feedback

As much as we love statistics here at Mailjet, we also know they can only tell you so much. So how can you dig a little deeper? Why not go ahead and ask your subscribers?

It’s a bit like a quality control test. There are a ton of questions you can ask your subscribers that could give you valuable insight into your sending, and help you understand what you should be placing more focus on. Questions about the kind of content to include, promotions they want to see, products they love and the frequency of the sending are just a couple suggestions.

Headspace asking for feedback

Summing up

Email marketing can be a daunting task. From the subject line, to the subject of your email, all the way to how to gage how interested your customers are in your campaigns, there is a lot to consider. If you keep in mind these 12 best practices, it will make it easier to know what to focus on, and what to prioritize. From the planning of your email, all the way down to the tracking of the stats, Mailjet can help you make the most of these email marketing best practices.

Do you have any email marketing best practices that you want to share? Let us know on Twitter!

Understanding In-Housing: Bringing Marketing Functions Home

Understanding In-Housing: Bringing Marketing Functions Home, a research by Mailjet and the DMA.

In-housing is an increasingly discussed topic across our industry in recent years – often, because it challenges the transparency of some agency practices.

To dig deeper, Mailjet has partnered with the DMA to look more closely at how and why brands are in-housing key marketing functions, by exploring the benefits, challenges, and potential future performance.

The research is a fascinating insight into the key drivers and outcomes that businesses have already seen from their experience of in-housing functions, as well as the challenges ahead in understanding and realising the full benefits of bringing other functions within an organisation.

Download the full research report ‘Understanding In-Housing: Bringing Marketing Functions Home’ to get a closer look at the state of in-housing, its benefits and challenges.

Research report banner

Use Mailjet’s API with Postman

Developers are always searching for new and better applications, libraries, integrations, and ways to work. This is why each developer has a wide range of tools at their disposal. It’s the same for you, isn’t it?

Now you can send your emails better and easier with Mailjet and Postman – which we know will be your new favorite application (if this isn’t the case already). Let’s dive in.

What is Postman

When you are setting up your transactional emails flow, a lot of checks and test API calls are needed to see if everything is working. Having an intuitive tool with easy to use libraries of API calls can be your salvation in a situation like this. This tool will be your best friend. Why? Because it’s going to make your life a whole lot easier. So, drumroll, please… 🥁 Say ‘hello’ to Postman.

Postman is a widely used API tool that helps 7 million developers and more than 300,000 companies access millions of APIs every month. It provides features for designing, testing, mocking, and debugging API requests to make API development easier for everyone.

Postman offers a development environment that you can use to build, publish, document, design, monitor, test, and debug APIs. It allows users to set up all the API expects and checks the response of your request. It’s really easy to use it, you will just need to log in to your own account to access files anytime, anywhere. But let’s have a closer look at what Postman offers and how it works.

How to use Postman

If you still haven’t downloaded Postman, you can get it here for Mac, Windows, or Linux.

Once you’ve installed Postman, you will have to create an account, select the workspace tools you need and click Save My Preferences. Now you’re ready to use Postman! The Postman application will open and this is what you’ll see:


Let’s have a look at a few of the most important buttons:

  • New – This is where you will create a new request, collection or environment.
  • Import – This is used to import a collection or environment. There are options such as import from file, folder, link or paste the raw text.
  • My Workspace – You can create a new workspace individually or as a team.
  • Invite – Collaborate on a workspace by inviting team members.
  • History – Past requests that you have sent will be displayed in History. This makes it easy to track the actions that you have done.
  • Request tab – This displays the title of the request you are working on. By default, “Untitled Request” will be displayed for requests without titles.
  • HTTP Request – Clicking this will display a dropdown list of different requests such as GET, POST, COPY, DELETE, etc.
  • Request URL – Also known as an endpoint, here you’ll identify the link with which they API will communicate.
  • Params – This is where you will write parameters needed for a request such as key values.
  • Authorization – In order to access APIs, proper authorization is needed. It may be in the form of a username and password, bearer token, etc.
  • Headers – You can set headers, such as content type JSON, depending on the needs of the organization.
  • Body – This is where one can customize details in a request commonly used in POST request.

Using Postman with Mailjet’s API

Let’s try an easy request with Mailjet’s API and see how it works. We will take a simple API call for sending an email with API 3.1:

# This call sends a message to one recipient.
curl -s \
    -X POST \
    -H 'Content-Type: application/json' \
    -d '{
                  "From": {
                           "Email": "",
                           "Name": "Mailjet Pilot"
                  "To": [
                         "Email": "",
                         "Name": "passenger 1"
                  "Subject": "Your email flight plan!",
                  "TextPart": "Dear passenger 1, welcome to Mailjet! May the delivery force be with you!",
                   "HTMLPart": ">Dear passenger 1, welcome to Mailjet! May the delivery force be with you!" 

We will start with the authentication part. You’ll have to select Basic Authentication and enter your API key and secret key that you can find here.


Now we will copy the endpoint to the Enter request URL and choose the method we need. In our case, the method is POST and the endpoint is We will go to the Body and select the “raw” view and JSON(application/JSON) as a framework.


Now we will copy the body of the API call we have as an example above and replace part of the information. I mean, we do need a real email address for the sending, right? 😉 But here’s how it will look like before replacing the data:


Once you have replaced the information with your own data, you will have to click on the Send button that is to the right of the field where we put the endpoint. If everything was correctly set up, you will see the response in the payload, in the field below the one with API call.


We can see that the status is 200 OK (so, everything is fine with our API call) and the time that it took to execute the call and the size of the call. The payload contains all the information from Mailjet to check what happened to your message. And that’s it! Now you know how Postman works.

Something that is worth mentioning too is that Postman stores all of the calls that you’ve ever made in their History tab. This way, you can go back to a previous configuration and reuse it, without the need to code everything again. This is useful if you want to compare two API calls or their response, or if there is a configuration that you need to call often to check its response.

Postman also offers a useful feature called “Collections” that allows you to organize and group the API calls, or import already existing ones. Each collection is actually like a folder that contains multiple API calls, and allows you to add sub-collections (or additional folders) as well. Collections are as useful as the History tab when you have to test the same endpoints multiple times. You can group your API calls in different folders so you can easily find them.

Personally, we love Postman because it is easy to use and it offers a lot of collaboration features that let us work together a lot more efficiently. Want to know more about that? Stay tuned and we’ll be publishing a post about it soon.

But, as we mentioned, the collections in Postman make your work easier, do you think that we’re going to make you copy all of your API calls by hand? Of course not.

How to add Mailjet’s API collection on Postman

If you already love Postman, you can download Mailjet’s API Postman Collection using the button below.

This button is also available in our API documentation if you want to check it first.

Once you have imported the collection in your Postman application, you can easily access all of our endpoints and do your tests. This will save you a lot of time. Postman will provide you with the detailed payloads for each API call and do the troubleshooting (if needed, because we know you are gods of coding) easier.

How Mailjet’s API collection will look like in Postman

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