Company lists · Data refreshed September 2026

Top 25 Transactional email services worldwide

RevenueBase identified 345 transactional email services worldwide as of September 2026 and tracks 4,701 professional contacts across them, including 1,662 with verified work emails. The United States is the largest market and New York the largest hub.

This list covers transactional email services worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 22, 2026. Country and city lists for transactional email services follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 22, 2026 86% judged on-target in blind review
345Companies
4,701Contacts tracked
1,662Verified emails
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The 25 largest transactional email services worldwide

Ranked by team size
Top 25 of 345 transactional email services worldwide, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to transactional email services: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidencePortland, OR, United StatesHQ checked Sep 22, 2026201-500446 contacts →

Indirect evidence

“Create personalized customer journeys that engage and convert with our versatile customer engagement platform.”

Source: RevenueBase Database · checked Sep 22, 2026
2Indirect evidenceNew York, NY, United StatesHQ checked Sep 22, 202651-200197 contacts →

Indirect evidence

“Our mission is to solve customer experience.”

Source: RevenueBase Database · checked Sep 22, 2026
3Partial evidenceSan Antonio, TX, United StatesHQ checked Sep 22, 2026201-500190 contacts →

Partial evidence

“Sinch Mailgun is the leading email delivery service for businesses around the world.”

Source: RevenueBase Database · checked Sep 22, 2026
4Partial evidenceUnited StatesHQ checked Sep 22, 202651-200141 contacts →

Partial evidence

“Kit is the email marketing platform built for creators who mean business.”

Source: RevenueBase Database · checked Sep 22, 2026
5Indirect evidenceUnited StatesHQ checked Sep 22, 2026501-1,000134 contacts →

Indirect evidence

“Sendinblue is now @Brevo”

Source: RevenueBase Database · checked Sep 22, 2026
6Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 22, 202651-200122 contacts →

Partial evidence

“In 2005, we started as a web design agency, but we soon discovered email marketing and fell in love with it.”

Source: RevenueBase Database · checked Sep 22, 2026
7Partial evidenceSt Louis, MO, United StatesHQ checked Sep 22, 202651-200115 contacts →

Partial evidence

“Benchmark helps busy marketers move faster and make a bigger impact with email.”

Source: RevenueBase Database · checked Sep 22, 2026
8Partial evidenceWaverley, South AfricaHQ checked Sep 22, 202651-20094 contacts →

Partial evidence

“Everlytic is a marketing messaging and automation platform that helps your business communicate better, smarter, and faster over email, SMS, voice broadcasting and web push.”

Source: RevenueBase Database · checked Sep 22, 2026
9Indirect evidenceFreiburg, GermanyHQ checked Sep 22, 202651-20090 contacts →

Indirect evidence

“Inxmail ist der serviceorientierte Tech-Spezialist für sichere, datengetriebene Kommunikation im E-Mail-Marketing.”

Source: RevenueBase Database · checked Sep 22, 2026
10Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 22, 202611-5088 contacts →

Partial evidence

“Mailmodo is a complete email marketing solution enabling users to create and send app-like interactive emails to improve email conversions.”

Source: RevenueBase Database · checked Sep 22, 2026
11Indirect evidenceMalmö, SwedenHQ checked Sep 22, 202611-5086 contacts →

Indirect evidence

“Your data holds more potential than you think.”

Source: RevenueBase Database · checked Sep 22, 2026
12Indirect evidenceCaba, IndiaHQ checked Sep 22, 202651-20080 contacts →

Indirect evidence

“Activa tus estrategias de marketing, personaliza cada interacción, toma decisiones basadas en datos y maximiza tu performance a través de nuestra plataforma de marketing…”

Source: RevenueBase Database · checked Sep 22, 2026
13Indirect evidencePrague, Czech RepublicHQ checked Sep 22, 202651-20068 contacts →

Indirect evidence

“Ecomail je moderní e-mail marketingová platforma pro rozesílku newsletterů a SMS, automatizovaný e-mailing a rychlý růst databáze kontaktů.”

Source: RevenueBase Database · checked Sep 22, 2026
14Partial evidenceMoscow, RussiaHQ checked Sep 22, 202651-20061 contacts →

Partial evidence

“UniSender is a №1 email and SMS sending service in the CIS region.”

Source: RevenueBase Database · checked Sep 22, 2026
15Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 22, 202611-5056 contacts →

Partial evidence

Email for developers”

Source: RevenueBase Database · checked Sep 22, 2026
16Partial evidenceBarcelona, SpainHQ checked Sep 22, 202611-5051 contacts →

Partial evidence

“Automatically target customers based on how they interact across all channels: email, SMS, Facebook Messenger.”

Source: RevenueBase Database · checked Sep 22, 2026
17Partial evidenceSzczecin, PolandHQ checked Sep 22, 202611-5047 contacts →

Partial evidence

“All the email marketing and delivery tools you need to communicate with your customers.”

Source: RevenueBase Database · checked Sep 22, 2026
18Partial evidenceOttawa, ON, CanadaHQ checked Sep 22, 202651-20047 contacts →

Partial evidence

“SMTP is one of the early pioneers of cloud-based email services and is now part of Ziff Davis, Moz Group and Campaigner.”

Source: RevenueBase Database · checked Sep 22, 2026
19Partial evidenceSan Diego, CA, United StatesHQ checked Sep 22, 202651-20046 contacts →

Partial evidence

“Truly unified email, SMS, reviews, and forms.”

Source: RevenueBase Database · checked Sep 22, 2026
20Indirect evidenceRastede, GermanyHQ checked Sep 22, 202611-5046 contacts →

Indirect evidence

“CleverReach ist eine der führenden Lösungen für E-Mail Marketing.”

Source: RevenueBase Database · checked Sep 22, 2026
21Strong evidenceBangalore, IndiaHQ checked Sep 22, 202651-20045 contacts →

Strong evidence

“Kasplo is a cloud-based email delivery and management service designed to help businesses send transactional and marketing emails on a large scale.”

Source: RevenueBase Database · checked Sep 22, 2026
22Indirect evidenceBerlin, GermanyHQ checked Sep 22, 2026201-50038 contacts →

Indirect evidence

“MessageFlow is a send-it-all platform that makes cross-channel communication easy and effective.”

Source: RevenueBase Database · checked Sep 22, 2026
23Indirect evidenceSao Paulo, BrazilHQ checked Sep 22, 202651-20038 contacts →

Indirect evidence

“A SendPulse é uma plataforma de marketing orientada por IA para negócios prontos para escalar, ajudando a automatizar e-mail marketing e chatbot para WhatsApp.”

Source: RevenueBase Database · checked Sep 22, 2026
24Partial evidenceDenver, CO, United StatesHQ checked Sep 22, 2026201-50038 contacts →

Partial evidence

“SendGrid is a proven cloud-based customer communication platform that successfully delivers over 45 billion emails each month for Internet and mobile-based customers like Airbnb…”

Source: RevenueBase Database · checked Sep 22, 2026
25Partial evidencePune, IndiaHQ checked Sep 22, 202651-20035 contacts →

Partial evidence

“We are a marketing technology company that provides a state-of-the-art email, SMS & web-marketing platform.”

Source: RevenueBase Database · checked Sep 22, 2026

Showing 25 of 345 transactional email services worldwide

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Transactional email services worldwide at a glance

As of Sep 22, 2026
35.4%Verified-email coverage
13.6Average contacts per company
1-10Median size (employees)
2.9%Largest-city concentration · New York
Sep 22, 2026Page data refreshed

Companies by employee count

1-10
173
11-50
123
51-200
37
201-500
10
501-1,000
1
1,001-5,000
1

Email recency is reported on each country list linked below.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among transactional email services, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
Coverage
Every country. Country and city lists for transactional email services are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “transactional email services”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names transactional email services), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among transactional email services, and records with no verified work email.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 1,662 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 22, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Transactional email services by location

1 lists · largest first

Every Transactional email services list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names transactional email services, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many transactional email services are there worldwide?

RevenueBase identified 345 transactional email services worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

customer.io, headquartered in Portland, tops this list with the largest team on record.

Which country has the most transactional email services?

The United States leads with 71 companies. Every transactional email services list by country and city is linked on this page.

Which city has the most transactional email services?

New York leads with 10 headquartered companies, followed by Austin (8) and London (5).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,662 verified decision-maker contacts tracked across these 345 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 22, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.