Course 3 • Lesson 7

Choosing an ESP service

There are a number of solid email service providers to choose from. How do you decide which is the best for your team, user base, and budget? This lesson will give you insight into the vendor landscape and walk through some key considerations when it comes to selecting an email tool.

You're probably reading this because you managed to pull together enough users that personalized messages from your Gmail account are no longer cutting it. Or you've been in the email-slinging game for awhile and you're ready to upgrade your solution. Either way, congrats on hitting your email milestone, you've come to the right place to understand the next steps you should take.

Choosing an email tool has changed… buyer beware!

Recent changes in the ESP landscape have made choosing an email service provider (ESP) less straightforward than it used to be. Some of those trends include the following:

  • Larger vendors keep acquiring email tools. ExactTarget and Pardot were acquired by Salesforce. Marketo was acquired by Adobe. Oracle acquired Eloqua. And the list goes on and on. Marketing suite or bust, right?

  • Email tools are opting for less specialization to generate broader appeal. Email providers that were originally geared toward small and mid-sized businesses like Constant Contact and Campaign Monitor moved up-market in an attempt to meet the needs of enterprise companies. Similarly, ESPs that had been primarily transactional auto-response email providers, like Sendgrid, began adding more functionality as they matured.

  • Up-and-comers have entered and shaken up the market. Some new vendors in the space—many of whom were originally sales tools or mobile marketing platforms—are now trying to expand their offerings and market themselves as ESPs or marketing suite alternatives.

Why email is still a big deal

Email has often been criticized as "too spammy," leading some to predict that it will eventually die. (I'm not crying, you're crying.) However, email remains a primary driver of acquisition, revenue growth, customer engagement, and customer service to this day. This is particularly true for B2B marketers--59% of whom report that email is their top revenue-generating channel. So, dry your eyes, because it's safe to say email is going to be here for the long haul.

Considerations for choosing an email service provider


First Dimension: Size of Contact List

In this lesson, we'll share which ESPs are best suited for various contact list sizes--ranging from tools that enable basic email functionality for smaller contact lists (without all the bells and whistles or integrations), to full-blown email marketing automation platforms with sophisticated drip-nurture and trigger-based logic that would be more appropriate for large-scale contact databases.

Second Dimension: Best for B2C vs. B2B

We'll also share which tools are specialized for B2C audiences, which focus on managing frequency of messaging and promotions, or B2B audiences, which have a greater emphasis on lead nurturing.

Other Important Considerations

Naturally, it's also prudent to look at cost, ease of implementation, and how seamlessly the ESPs integrate with other existing channels such as Customer Relationship Management (CRM), performance marketing tracking, etc.

The email service provider landscape


Braze (formerly Appboy) established itself as a mobile-first CRM with powerful text and push messaging features. With recent enhancements to its email marketing functionality and the addition of a visual journey builder, Braze has become a lifecycle engagement platform with an emphasis on highly personalized, targeted customer messaging.

Top features:

  • Push and SMS notifications

  • Visual customer journey builder

  • Automated multi-channel messaging

  • Strong customer support

Great for:

  • Objective: Marketers using push and email

  • Company Size: Mid-market to enterprise

  • Contact List: Any size

  • Industry: Any industry, but especially useful for push-centric B2C

A data-driven marketing platform for newsletter creation, transactional emails, and customer profile triggered messaging, provides a flexible and easy-to-implement solution for data-driven startups and SMBs. It allows for A/B testing, conversion tracking, drip-nurture campaign functionality, and the ability to set advanced time settings.

Top features:

  • Flexible in mapping customer behavioral data

  • Uses Shopify's open-source Liquid logic

  • Enables sophisticated activation and retention-oriented email campaigns from real-time triggers on customer behaviors

  • Orients around the user and how they've interacted with sent messages

Great for:

  • Objective: Implement a seamless plug-and-play tool for customer messaging

  • Company Size: SMBs and startups

  • Contact List: Any size

  • Industry: E-commerce primarily


Drip is an email marketing automation platform well-suited for B2B marketers. The visual campaign builder offers customizable triggers, actions, and integrations to create automated campaigns based on customer behavior.

Top features:

  • Ease-of-use

  • Workflow builder

  • Can resend with different subject line to users who didn't initially open

  • Friendly pricing

Great for:

  • Objective: Advanced marketing automation with a lean team

  • Company Size: SMBs and startups

  • Contact List: Can handle relatively small lists to mid-sized lists

  • Industry: Any industry


More than just an email service provider, Hubspot provides additional functionality across social media, lead generation, and CRMs. Touting themselves as an "Inbound Marketing Platform," Hubspot helps marketers both create demand through content and nurture leads through email campaigns. Hubspot is very easy to use and navigate, and as such, they are appropriate for large and small businesses alike. However, the pricing model is dependent on the total number of contacts in your database, so it becomes cost-prohibitive for very large-scale businesses.

Top features:

  • Many built-in API integrations

  • Gives visibility across additional touch points on social media platforms

  • Lead-generation identification capabilities

  • Assists with inbound marketing and demand generation

Great for:

  • Objective: A full suite of marketing automation solutions and tools for inbound marketing

  • Company Size: Any size

  • Contact List: >25K contacts

  • Industry: Can be used for either B2B or B2C, but can become cost prohibitive for large B2C lists


A newer player in the ESP space, Iterable is a multi-channel customer engagement and marketing automation platform. It focuses on offering less-technically-savvy marketers access to intuitive yet powerful drag-and-drop automation flows, dynamic personalization and segmentation features that would typically require more in-depth engineering support and resources.

Top features:

  • Ease of use

  • Multivariate testing

  • Omnichannel campaigns

  • Personalization

Great for:

  • Objective: Unlock multi-channel marketing automation with minimal engineering support

  • Company Size: Mid-size

  • Contact List: 100K+

  • Industry: More suited for B2C


Known for being user friendly, MailChimp is a fan favorite for many startups with small marketing teams. Not only is it quick to get up and running, but the templates are intuitive and straightforward to navigate. Though they still lack some features such as allowing the creation of automated A/B split tests into subject lines, they have more recently added marketing automation functionality.

Top features:

  • Quick to set up

  • Easy to use

  • Built-in design templates

  • Doesn't require a developer or designer

Great for:

  • Objective: Deploy an easy-to-use email marketing tool

  • Customer Company Size: Small to mid-size

  • Contact List: 100+

  • Industry: Any industry


Often thought of as the 10,000-pound gorilla in the email marketing automation space, Marketo became an early market leader for multi-campaign email management. However, more functionality means a higher price tag and sophisticated users to operate it. Marketo is great for mid-market to enterprise-level B2B customers already on the Adobe suite. It might not be appropriate for very small businesses due to the cost or the advanced skill level and training required to operate it. That said, we are a fan—Marketo is what we use here internally at Segment.

Top features:

  • Deep SFDC integration for advanced lead scoring

  • Easy to use UI and templates

  • High level of functionality and integrations

  • Tried and true name brand

Great for:

  • Objective: Automate email marketing and integrate with CRMs

  • Company Size: Any size, but must be spending at least $3-$5M per year in marketing.

  • Contact List: 100K+

  • Industry: Usually most appropriate for B2B but can be used to manage sensitive lists requiring privacy in the financial or healthcare spaces

Oracle Marketing Cloud

Oracle Marketing Cloud offers an integrated portfolio of cloud-based sales and marketing applications, including Eloqua and Responsys. With its lead scoring, webinar management, and Salesforce integration, Eloqua is well-suited for mid-market to enterprise-level B2B companies.

Top features:

  • Comprehensive (uses former Responsys and Eloqua platforms)

  • Appropriate for B2B and B2C

  • Automation and routing

  • Requires sophisticated developer integration

Great for:

  • Objective: One of the most comprehensive email suites available

  • Company Size: Large enterprises

  • Contact List: 100K+

  • Industry: Any industry

Salesforce Marketing Cloud (formerly ExactTarget)

Salesforce Marketing Cloud is a powerful marketing automation platform for marketers. Formerly ExactTarget, it comprises Marketing Cloud's email, mobile and web marketing suite, and focuses on engagement through personalized customer journeys.

Top features:

  • Comprehensive

  • Appropriate for B2C

  • Automation and routing

  • Great for companies who can deploy developers for deep customization

Great for:

  • Objective: Use one of the most comprehensive email suite available

  • Customer Company Size: Large Enterprise (Marketing Cloud)

  • Contact List: 100K+

  • Industry: Works for all sectors; especially well-suited for retailers

Salesforce Marketing Cloud (formerly Pardot)

Salesforce Marketing Cloud is a powerful customer relationship management (CRM) and marketing automation platform for B2B marketers. With its lead scoring and nurturing features, Pardot best suits mid-market businesses in need of advanced marketing automation functionality.

Top features:

  • Comprehensive features and integrations

  • Appropriate for B2B

  • Automation, lead scoring, and routing

  • Requires sophisticated developer integration

Great for:

  • Objective: One of the most comprehensive email suites available

  • Company Size: Mid-size companies

  • Contact List: 100K+

  • Industry: Works for all B2B industries

Making the final call

Getting to the core differences of the email tools listed above may seem like an arduous task. However, one benefit of the relative maturity of the email marketing space is that each vendor will cover the basics and has a solid roster of customers that you can learn from. While certain tools are much better suited for certain sized businesses and industries, each tool will be able to accomplish the basics of engaging with your user base at scale in personalized ways. This is especially true if you've set up your analytics with a tool like Segment.

For more information on the email service providers that Segment offers, check out our catalog of integrations here.

Side note: Are you an email service provider that's interested in snagging a spot on this list? Get more information on Segment's partner program here.


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Course: 4: Building a data driven company

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