Choosing an ESP

Choosing an Email Service Provider: 11 Key Questions Before You Buy

The email service provider (ESP) you choose to use is where a lot of the email marketing magic happens. You literally can't send marketing emails without one. The truth is, while there are tons of solutions in most martech stacks, there aren't many that are more important than an ESP. So, whether you're choosing an email service provider for the first time or looking to switch - it's a major decision.

In this article, we'll take a look at some key questions to consider as you evaluate ESPs and decide which one is right for your program's needs.

Why choose a new email service provider?

If you're choosing an email service provider, you're probably working at a new business or startup that needs to find the right marketing tools. Otherwise, you're breaking up with your old ESP and need to make a change.

Here are a few of the main reasons why marketers find themselves choosing an email service provider:

  • Pricing for their current ESP suddenly took a jump.
  • The current ESP doesn't have the features the sender needs.
  • The current ESP is too complex and features aren't necessary.
  • Poor service and support experience.
  • The sender has had deliverability issues with their current ESP.
  • There's no way to integrate the ESP with other platforms and applications.

A study featured on found that the top three reasons marketers switch ESPs were:

  1. Technical limitations (50%)
  2. Email deliverability (41%)
  3. Substandard user experience (30%)

All these are totally legitimate reasons for saying "so long" and choosing a new email service provider. If you're on that journey right now, here's what you should be asking...

1. Does the ESP have trials or free plans?

Can you try it before you buy it? While this depends on the ESP, many have a free trial option. For instance, Sinch Mailjet has a free plan that allows up to 6,000 emails in a month. That might work for a small local business, but if you’re sending out email marketing campaigns, chances are you’ll use that up pretty quickly. However, this sort of trial helps you understand what an ESP has to offer before you say yes.

Be aware that features may be limited on those free plans from ESPs. A limited-time trial of a paid plan may give you a better idea of what to expect. In many cases, you can reach out to the ESP and get a custom demo to answer all your questions.

Regardless, by taking an ESP for a test drive, you can get a feel for user functionality, test deliverability, how to upload lists, and even build out an email campaign to get a feel for the software.

2. Does the ESP fit your email marketing budget?

After you’ve taken the ESP for a trial run, it’s important to get down to brass tacks when it comes to pricing. While this shouldn’t be the most important factor when picking your ESP, it usually ends up being so.

When choosing an email service provider, two significant factors that impact pricing are the size of your list (number of contacts) and how many emails you need to send each month (send volume).

If you need to determine whether an ESP's pricing is worth it, check out this advice on calculating the ROI of email. If you need to convince decision-makers that the ESP you like is worth the price tag, check out our article on email marketing budgets.

3. How will you build your email templates?

When choosing an ESP, your team's knowledge of HTML and CSS is a big factor. Will they be using a drag-and-drop email builder or coding their own campaigns? Ideally, an ESP will offer the flexibility to do both. That way marketers with less coding knowledge can build emails while developers still have control and can access the code to do their thing.

There are plenty of low-code or no-code email marketing solutions out there. But evaluating the flexibility and versatility of the tool used to build your emails is important. The user experience and capabilities will vary from one ESP to the next.

You may also want to consider the types and variety of pre-made email templates the ESP offers its users. These can be useful, especially if you're a one-person email team.

Gallery of Mailjet email templates
Email newsletter templates from Sinch Mailjet

Don’t forget, when customizing your template, a simple tweak in the HTML can cause display issues for various clients and devices. Be sure to exhaustively test your email before you hit send.

4. How will you measure success?

What you don’t know can hurt you, so you need to find an ESP that’ll go beyond just tracking opens and clicks. That means evaluating the types of email analytics the ESP offers. If there's a certain metric that's important to you, such as tracking dark mode opens or understanding who uses Apple Mail Privacy Protection (MPP), look into it before you buy.

To create a killer campaign that spurs your subscribers into action, you must “know your audience.” This boils down to leveraging the right email analytics and reporting tools to uncover the audience’s interests and pain points. Look through your next potential ESPs repertoire of tracking tools to know you’re getting the most bang for your buck.

For example, many ESPs offer granular reporting about subscriber activity reports. Based on this data, you can employ email list segmentation to retarget your audience for even better success rates.

5. Does the ESP have reliable support?

Will someone be there to lend a helping hand? We know finding your way around new marketing technology is difficult. That’s why it’s important to check what kind of support a potential ESP can offer. For instance, some ESPs are more barebones. Others have dedicated support teams to help you when you’re nailing down new automation triggers or uploading a new list.

Your ESP should offer both online and phone customer support and training. The customer service offered by your ESP will be critical to your success.

6. Can you segment your lists?

That’s right. How can choosing the right ESP help you slice and dice your data with list segmentation? The ability to segment is becoming a necessity for most email marketing strategies.

With proper analytics and reporting in place, you can segment your list by factors ranging from gender to more granular characteristics like geolocation, engagement, device, and more. Check out some email list segmentation results below:

Chart on email segmentation benefits

Since the majority of email service providers will provide the ability to segment your list, what you really need to find out is how it works and what kinds of segments you can create. Some senders may end up using other automation tools, like a customer data platform (CDP) or customer relationship management (CRM) software to help with segmentation. (In that case, pay attention to #8)

7. Can you personalize your email campaigns?

Segmentation is an excellent way to get the most out of an ESP, but email personalization takes it to the next level. Personalized emails are the best way to turn your campaigns into a 1-to-1 inbox experience. Using the data you have collected about individual subscribers, you can do much more than add names to subject lines. That is ... as long as the email service provider you choose makes that possible.

Evaluate your email personalization plans and needs for the near future. For example, if you want to include personalized product recommendations in your emails, will the ESP you're considering make the process straightforward or complicated?

Personalization gets complicated. Find out how intuitive the process is with the ESPs in your consideration set. And, as we've mentioned with segmentation, the integration of platforms is another important factor for powerful personalization.

8. Which third-party integrations work with your ESP?

While your ESP should be chock-full of features, it’s usually not a one-stop shop for all your marketing efforts. Email marketing is only one channel in your digital strategy, so it’s important that your ESP integrates with other applications, like eCommerce or social media platforms, to aid in the effectiveness of your campaigns.

For example, if you use Shopify, you might want to find an ESP that integrates with it, so your eCommerce store connects to your email marketing. This way, you can create targeted campaigns, automate helpful product follow-ups, and send back-in-stock messaging.

Integrations connect your marketing technology, which makes things more efficient and effective. Find out if your current SaaS solutions are able to integrate with the email service providers you're considering.

9. Can you run email A/B testing?

As digital marketers, we can’t rely only on our intuition when deciding what will resonate with our audience. Instead, we need hard facts and in-depth analytics to point us in the right direction for the best conversion optimization – and that’s where A/B testing comes into play.

The most common elements to A/B test in an email campaign are subject lines, email content, send time, and differing calls-to-action (CTAs) to find which email elements work best. Split testing can vary in complexity and results, but if you’re new to the world of A/B testing, consider starting with the good ol’ subject line test. A/B subject line tests are simple in nature but can be wildly effective.

10. Does the ESP adhere to data privacy compliance?

With the rise of data protection laws like the GDPR and CCPA, it’s important to ensure your subscribers’ personal information is safe and properly handled.

As data processors, ESPs must follow data processing guidelines and keep your customer's sensitive information safe. However, each ESP differs in exactly what safety and security features they have in place. Don’t forget to compare the data security policies of each ESP before you make a decision.

If you are based in or have subscribers living in the European Union (EU), GDPR compliance is a big consideration. That includes how your ESPs transfers subscriber data across the Atlantic and where it stores EU consumer data. To find out more about all of this, read a data privacy officer's take on the situation.

11. How do they do with email deliverability?

If you choose an ESP and start having email deliverability problems that are not your fault, it's kind of an issue, right? That can sometimes happen when you're sending emails from a shared IP address.

Let's say your ESP is letting senders with shady reputations send spam from the same IP address as you're using. That's going to make you look like a possible spammer too. It could degrade your reputation among mailbox providers and drag your deliverability down. For that reason, review the ESP's "Acceptable Use Policy", which describes guidelines senders must maintain when using the platform.

You can also look for additional features that support strong deliverability. That includes blocklist monitoring, spam testing, deliverability metrics, and email verifications to keep your list clean.

Two ESPs for your consideration...

Just to be perfectly clear, Email on Acid is not an ESP. Some of the features we provide, (email analytics, previews, an email editor, etc.) may also be available in ESPs, but you don't use our solution to send emails.

However, we do have two sister brands in the Sinch Email family that are ESPs. If you're choosing an email service provider, we think you should definitely consider Sinch Mailjet and Sinch Mailgun. Here are some important details on each solution.

More about Mailgun

Sinch Mailgun logo

The Mailgun email sending platform is ideal for high-volume senders such as enterprise organizations that need to deliver a lot of mail. Mailgun was made for developers, engineers, and IT professionals. It's known for its robust and flexible Email API, which aids in integration. Another Mailgun strength is in delivering automated, transactional emails, which get sent from a reliable, rock-solid email infrastructure.

Other features and benefits include:

  • Deliverability: Mailgun provides a wide array of deliverability features as well as a complete suite with Mailgun Optimize.
  • Send Time Optimization (STO): This feature helps senders get emails to the inbox at the perfect time for individual subscribers.
  • SMTP sending: In addition to the API, Mailgun provides cloud-based SMTP services.
  • Speed of delivery: Important messages hit the inbox in record time with Rapid Fire and Burst Sending.
  • Security and compliance: Mailgun takes email security and privacy compliance super seriously. Check out their guide to learn more.

Even though Mailgun is a more technical email service provider, you can use it to build and send marketing emails as well.

Maillgun also works with B2B SaaS partners (such as CDPs, CRMs, and other forms of marketing automation) who use our platform as their email sending engine.

More about Mailjet

Mailjet by sinch logo

Mailjet is an email service provider that has digital marketers in mind. This software solution is what you'd expect in a traditional ESP. It's used by entrepreneurs and small businesses as well as big brands and enterprise organizations. That's because building beautiful, responsive emails with Mailjet's Email Editor is so easy and intuitive.

Other features and benefits include:

Mailjet got started in France and still has offices there as well as data servers located in the EU. That makes GDPR compliance a lot easier, and Mailjet has always been a reliable leader in this area.

ESPs and email testing

No matter what email service provider you choose, you've got to test each campaign before you hit send. And you can do that with Sinch Email on Acid regardless of your current or future ESP.

When it comes to how designs are rendered, email clients don't care which ESP you choose. They have their own ways of doing things. What looks great in Apple Mail might not work in Gmail. What works perfectly in Yahoo Mail may fall flat in Outlook inboxes. Plus, you've also got to consider mobile devices and dark mode!

With Email on Acid, you can send a test email straight from your ESP of choice and preview how it looks on all the major clients and devices. Unlike our competitors, we offer unlimited testing with every plan. So as you consider switching ESPs, think about adding our email quality assurance solutions to your tech stack too.

Simplify the Email QA Process and Deliver Perfection

What’s the best way to run through your pre-send checklist? With Sinch Email on Acid’s Campaign Precheck, we’ve simplified the process and set everything up for you. Use it to double-check your content, optimize for deliverability, ensure accessibility, and preview how campaigns look on more than 100 of the most popular clients and devices. All before you hit send!

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