Email Infrastructure and Service Providers

What is an ESP? A Guide to Working with Email Service Providers

minute read

Post Image

In our modern, endlessly connected world, if a business isn’t leveraging the power of email marketing to nurture customer relationships, is it even really a business?

A comprehensive email program has many strategic benefits—it increases conversions, raises brand awareness, and fosters customer loyalty. But, without the right infrastructure, that same program can become an unmanageable nightmare.

That infrastructure starts with your email service provider (ESP). Whether you’re a seasoned pro or just getting started, understanding the ins and outs of ESPs is essential for maximizing your email marketing efforts. Read on to learn more.

What is an ESP?

Not to be confused with your Mailbox Provider (MBP), an ESP is a marketing tool that allows you to send email marketing campaigns to a list of contacts. Gmail is an MBP, for example. Hubspot is an ESP.

From an organizational perspective, it’s a cost- and time-effective way to communicate with your customers on a 1-to-1 basis without wasting away sending individual emails to hundreds or thousands of subscribers (can you imagine?).

6 key features of ESPs

Your ESP should maximize your email marketing efforts, not hinder them. So, whether you’re a first-time buyer or shopping around for an ESP migration, be sure to keep an eye out for the following features.

List management

List management capabilities allow you to organize and segment your subscriber lists quickly and easily. You can create targeted groups based on various criteria, such as demographics, behavior, or engagement levels. This ensures that you send the right content to the right audience, maximizing engagement and conversion rates.

Campaign creation and design

ESPs with intuitive drag-and-drop editors and pre-designed templates simplify the process of creating visually appealing email campaigns. By leveraging these tools to customize layouts, add images, and craft compelling copy without any coding knowledge you can streamline your campaign creation and design and deliver professional and engaging emails that align with your brand all at once!

Campaign automation

With automation tools, you can set up triggered emails based on specific user actions or time-based events. Automated workflows make light work of nurturing leads, welcoming new subscribers, and re-engaging inactive ones. This time-saving feature ensures that your subscribers receive relevant content at the most opportune moments, improving overall engagement and conversion rates.

Email personalization

Just because you’re using an automated system, doesn’t mean you can’t customize your messaging! Depending on how advanced the personalization is, you could leverage your ESP to tailor emails to individual recipients by dynamically inserting subscriber names, location-based information, or personalized product recommendations. This further enhances the customer experience and fosters a greater sense of connection and loyalty to your brand.

Deliverability management

Maintaining a high deliverability rate is crucial for successful email marketing. ESPs monitor and manage deliverability issues, helping you avoid spam filters and improve your sender reputation. By complying with best practices and continuously refining your email list, you can ensure that your messages land in the inbox instead of the spam folder.

Analytics and reporting

ESPs usually offer analytics and reporting dashboards so you can track key metrics such as open rates, click-through rates, and conversion rates. This kind of data-driven insight is crucial as it allows you to measure the effectiveness of your campaigns, identify areas for improvement, and make data-backed decisions to optimize your email marketing strategy.

Incorporating these six key features into your email marketing strategy using an ESP will elevate your campaigns, deepen customer relationships, and drive tangible results for your business.

3 types of ESPs

From small businesses to large enterprises, there’s an ESP out there for everyone but not all ESPs are made the same. In fact, ESPs can be broken down into three groups.

All-in-one ESP

An all-in-one ESP is all-encompassing, offering a wide range of tools and features to manage various aspects of email marketing and beyond. An all-in-one ESP goes beyond just sending emails and includes additional functionalities to support a more holistic marketing approach.

Niche ESP

A niche ESP caters to a specific industry or target audience with a narrow focus on particular features or functionalities. Unlike all-in-one ESPs that offer a wide range of tools for various marketing needs, Niche ESPs concentrate on serving the unique requirements of a particular niche or market segment.

Self-hosted ESP

A self-hosted ESP, or Private Email Service, is a solution that businesses host and operate on their own infrastructure instead of relying on a third-party service provider. In this setup, the business manages all aspects of the email marketing system, including hardware, software, security, and maintenance.

What to consider when choosing an ESP

By now, you’re aware of the benefits, features, and even types of ESPs that are out there. However, you may be wondering what questions to ask your ESP (and your stakeholders) to ensure you select the best possible solution. Don’t worry, we’ve got you covered!

Do they fit your budget (even after you grow)?

Look for an ESP that can accommodate your current email marketing needs and can scale as your business grows. Consider pricing structures, including subscription fees, per-email charges, and any additional costs for extra features or higher email volumes. Ensure the pricing aligns with your budget and offers a suitable return on investment.

How high are their email deliverability rates?

As a sender, your reputation is everything. Choosing an ESP with a strong track record of high email deliverability rates ensures your emails reach the inbox instead of being flagged as spam, saving you (and your hard-earned rep) the headache.

How easily can they be integrated into your existing workflows?

Ensure that the ESP can seamlessly integrate with your existing systems, such as your customer relationship management (CRM) software, ecommerce platforms, or any other marketing and sales enablement tools. A smooth integration should streamline the transfer of data and empower internal stakeholders to leverage valuable customer insights (with permission, of course).

How helpful is their customer support?

Check the level of customer support provided by the ESP, including availability, response time, and support channels. Introducing any new tool or process to a business is going to have a learning curve which is why access to knowledgeable support staff is essential for troubleshooting issues promptly. Additionally, consider the availability of educational resources, documentation, and training materials to help you make the most of the ESP’s features.

Choosing the right ESP is a critical decision that can significantly impact your email marketing success. Carefully evaluate these factors to find an ESP that aligns with your business needs, goals, and budget, ultimately helping you achieve your marketing objectives effectively.

To recap…

We examined the pivotal role of an ESP in marketing campaigns. We also explored six key features of a good ESP, namely list management, campaign creation, automation, personalization, deliverability, and analytics.

Lastly, we looked at what key factors to consider when leveraging ESP marketing such as scalability, pricing, deliverability, reputation management, integration capabilities, and customer support. Ultimately, the right choice depends on your company’s needs and goals, whether it’s an all-in-one solution, a niche provider, or a self-hosted approach.

Whatever you choose, an ESP should be a trusted partner in your overall mission to connect with your audience—while you may be the brains of the operation, ESPs are the braun, handling the technical aspects and ensuring your messages reach the right people at the right time.

FAQs about ESPs

You’ve got Qs, we’ve got As. Read on for frequently asked questions about email service providers:

1. What is the difference between an ESP and a traditional email client?

An ESP is a service used by businesses to manage, automate, and send large-scale email marketing campaigns.

An email client is a software application focused on providing a user-friendly interface for individual users to read and send emails (think GMail and Outlook).

2. Can I use an ESP for personal email?

Unlike ESPs, personal emails aren’t built to manage large-scale marketing campaigns. Not only is there no way to track key metrics but sending large volumes of emails via a personal email will likely land you on a blocklist.

3. How do ESPs handle deliverability challenges?

Your ESP should work diligently to ensure your emails have the highest chance of landing in your subscribers’ inboxes, rather than the junk folder.

Given that their reputation is also on the line, a good ESP will often handle things, like:

  • Verifying sender legitimacy
  • Enforcing strong anti-spam and regulatory compliance policies
  • Streamlining your ability to clean and manage email lists
  • Tracking analytics to identify potential issues and optimize workflows 
  • Implementing email throttling and volume management to avoid triggering spam filters due to sudden spikes in email volume

4. Are ESPs suitable for small businesses?

If you’re leveraging email marketing for your business, regardless of size, an ESP is a must. ESPs are whitelisted to ensure that high volumes of emails are delivered without throttling and offer insights into how to optimize your emails and improve deliverability. 

5. Are there any limitations on the number of subscribers an ESP can handle?

While high-end ESPs usually have robust servers and systems that can accommodate substantial subscriber databases, most ESPs offer different pricing tiers based on the number of subscribers you have. 

Note that as your email list grows, you may need to upgrade to a higher tier to accommodate more subscribers. 

6. Can ESPs help with email automation and drip campaigns?


Although specific features may vary, ESPs are specifically designed to help with email automation and drip campaigns.

7. Can ESPs handle transactional emails, such as order confirmations and password resets?

Yes, ESPs allow you to set up automated triggers based on specific events or transactions, such as subscribing to a list, making a purchase, or requesting a password reset. When these triggers occur, the predefined email sequences are automatically sent to the relevant subscribers.

8. Are ESPs compliant with data privacy regulations, such as GDPR or CCPA?

Yes, any reputable ESP is committed to complying with data privacy regulations, such as the General Data Protection Regulation (GDPR) in the European Union and the California Consumer Privacy Act (CCPA) in the United States. For ESPs that operate globally, they must also comply with regulations regarding international data transfers, such as the EU’s Standard Contractual Clauses (SCCs) for data transfers outside the EU/EEA.

9. Can ESPs provide detailed email analytics, including open and click-through rates?

Yes, ESPs provide comprehensive analytics and reporting dashboards. Although specific features may vary, you can track key metrics such as open rates, click-through rates, and conversion rates. 

Ready to learn how your email program measures up?

Yes, the road to the inbox is growing ever more complicated—one in 10 legitimate emails aren’t even accepted by receiving mailbox providers! But don’t worry, we’re on the case.

To learn why global deliverability in 2023 is more challenging than ever and gain actionable insights on how to improve your deliverability, check out Validity’s 2023 Email Deliverability Benchmark Report.