Choosing the right email service provider

Alan Harris on July 27th 2018

This is our third post in a series about integration categories. Revisit our blog post “Choosing the right performance monitoring tool” here to read about our series objectives.

How choosing an email service provider (ESP) has recently evolved

Given how long email marketing has played a role in growth and customer engagement, one might think that the ESP landscape has already been covered extensively. However, due to recent consolidations and acquisitions in the ESP landscape, choosing an email service provider is not as straightforward as it used to be. 

In the past several years, we’ve seen several trends emerge. First, larger players have acquired ESPs that typically excelled in either business-to-consumer or business-to-business (B2B or B2C), resulting in consolidation. Secondly, tools became less specialized in nature: email providers that were originally geared toward small and mid-sized businesses (SMBs) (like Constant Contact and Campaign Monitor) moved up-market in an attempt to meet the needs of growing mid-market companies. Similarly, ESPs that had been primarily transactional auto-response email providers, like Sendgrid, began adding more functionality as they matured. Third, up-and-coming players have emerged to try to disrupt the market leaders. Some new vendors in the space — many of whom were originally sales tools — are now trying to expand their offering and market themselves as ESPs. Finally, all email vendors have had to increasingly think about privacy with recent regulatory changes. 

Why email is still a big deal

As long as email has been around as a channel, it has been criticized as “too spammy,” leading some to predict that it will eventually die. However, email has proven staying power and 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. In the coming years, we fully expect email to remain a big deal. We believe new privacy standards will, in the long run, drive more relevant, customized and interesting email communications, and that makes the selection of an ESP all the more critical. 

What will this piece cover?

In this blog post, we’ll provide a framework for evaluating ESPs, cover both the market-leading providers and some emerging players, and discuss which ESPs might be best for you based on your role, company size and objectives.

Zoom with margin

First dimension: size of contact list

In this analysis we will look at 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 will also discuss which tools are specialized for B2C audiences, which focus on managing frequency of messaging and promotions, and which focus on B2B audiences. We will discuss which tools include lead-nurturing capabilities.

In addition, we’ll explore cost, ease of implementation, and how seamlessly the ESPs integrate with other existing channels such as Customer Relationship Management (CRM), performance marketing tracking, etc. We’ll look at how intuitive they are to use and whether they’re more appropriate for an individual performance marketer or a sophisticated growth team requiring custom development. 

Email provider profiles


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 called Canvas, Braze has become a truly omni-channel lifecycle engagement platform with an emphasis on highly personalized, targeted customer messaging.

Top features:

  • Push and SMS notifications

  • Visual customer journey builder 

  • Automated multichannel messaging

  • Strong customer support

Great for:

  • Objective: Marketers using push and email

  • Role: Anyone in marketing

  • Customer 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. Offering fine-tuned optimization features, 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

  • Role: Any type of marketer

  • Customer Company Size: SMBs and startups

  • Contact List: Any size

  • Industry: E-commerce +


As one customer describes, “Drip is a lean email marketing automation platform laser-focused on workflows that are great for B2Bs.” The visual campaign builder has dozens of triggers, actions, and integrations to create automated campaigns with an intuitive workflow builder triggered by behavior so you can ensure recipients get the right message at the right time. Drip offers a free trial plan so prospective customers can get a feel for the simple, user-friendly interface.

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: Utilize advanced marketing automation with a lean team

  • Role: Tech-savvy email marketer

  • Customer 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 marketing 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. The pricing model differs in that it’s dependent on the total number of contacts in their database, so it can become 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: Use a full suite of marketing automation solutions and tools for inbound marketing 

  • Role: Performance Marketer, Growth Marketer, Customer Service

  • Customer Company Size: Any size, but need at least 25K contacts

  • 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

  • Omni-channel campaigns

  • Personalization

Great for:

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

  • Role: Email expert - Senior Lifecycle Marketing Managers

  • Customer Company Size: Mid-market to up-market

  • Contact List: 100K+

  • Industry: More suited for B2C


Known for its user-friendly branding and ease-of-use, MailChimp is a fan favorite for many startups with small marketing teams. Not only is it quick to get up and running without requiring development or design resources, but the templates are intuitive and straightforward to navigate. Though they still lack some features such as creating automated A/B split tests into subject lines, they have more recently added marketing automation functionality. 

Top features:

  • Quick to setup

  • 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

  • Role: Anyone in marketing or customer service

  • Customer Company Size: Small to mid-size

  • Contact List: 100+

  • Industry: Works for all sectors


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 using Salesforce. 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

  • Role: Performance Marketer, Growth Marketer

  • Customer 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 space

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. Responsys offers a deep level of dynamic content personalization with its relational table structure, and is better suited for B2C businesses looking to send high volumes of email, SMS and push messages.

Top features:

  • Comprehensive (uses former Responsys and Eloqua platforms)

  • Appropriate for B2B and B2C

  • Automation and routing

  • Requires sophisticated developer integration

Great for

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

  • Role: Email expert - Sr. Manager or Director level

  • Customer Company Size: Large enterprises

  • Contact List: 100K+

  • Industry: Works for all industries

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

  • Role: Email expert - Sr. Manager or Director level

  • Customer Company Size:  Large Enterprise (Marketing Cloud)

  • Contact List: 100K+

  • Industry: Works for all sectors, especially retail

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: Use one of the most comprehensive email suite available

  • Role: Email expert - Sr. Manager or Director level

  • Customer Company Size: Mid-market (Pardot) 

  • Contact List: 100K+

  • Industry: Works for all B2B industries

If you’re interested in exploring an email service provider, check out Segment. We make it easier for you to try different email, analytics, and optimization tools. 

We currently offer most of these email providers and tools on our platform. You can check out our full list of integrations here and request support for new ones here. To get started with Segment, you can create a free account here or sign up for a premium, business account demo here.

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