Company lists · Data refreshed November 2026

Top 25 Open source email marketing software companies based in the United States

RevenueBase identified 243 company matches for open source email marketing software companies associated with the United States as of November 2026 and tracks 2,756 professional contacts across them, including 703 with verified work emails. Austin is the largest hub.

This list covers company matches for open source email marketing software companies associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Nov 5, 2026 How this list was built
243Companies
2,756Contacts tracked
703Verified emails
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The 25 largest open source email marketing software companies based in the United States

Ranked by team size
Top 25 of 243 company matches for open source email marketing software companies based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 5, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchMorrisville, NC, United StatesHQ recorded Nov 5, 202651-200147 contacts →

Exact match

“We believe powerful connections propel business growth.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
2Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202651-200138 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3Exact matchSt. Louis, MO, United StatesHQ recorded Nov 5, 202651-200121 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4Exact matchDoylestown, PA, United StatesHQ recorded Nov 5, 202651-20095 contacts →

Exact match

“For over 20 years, AWeber has helped entrepreneurs and small business owners connect with their prospects and customers through powerfully-simple email marketing solutions.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202651-20084 contacts →

Exact match

“Flodesk makes simple, intuitive software tools to help entrepreneurs grow their businesses.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202611-5077 contacts →

Exact match

“Email for developers”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7Exact matchBoston, MA, United StatesHQ recorded Nov 5, 202651-20073 contacts →

Exact match

“Email & SMS for online brands that need the tools & coaching to grow sales.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
8Exact matchCambridge, MA, United StatesHQ recorded Nov 5, 202651-20067 contacts →

Exact match

“At Litmus, we know the importance of continuous innovation.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
9Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202611-5062 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchSanta Monica, CA, United StatesHQ recorded Nov 5, 202611-5061 contacts →

Exact match

“Nimble is your CRM for smarter email marketing, engagement, and business growth.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11Exact matchClaymont, DE, United StatesHQ recorded Nov 5, 202611-5059 contacts →

Exact match

“AiTrillion is a sales and marketing automation platform built to grow E-commerce via powerful modules to maximize customer engagement and retention.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
12Exact matchSan Mateo, CA, United StatesHQ recorded Nov 5, 202651-20042 contacts →

Exact match

“iPost is a leading email-sending platform purpose-built to solve real challenges in highly regulated and other data- and content-sensitive industries, including gaming, legal…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13Exact matchSan Diego, CA, United StatesHQ recorded Nov 5, 202651-20038 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14Exact matchCarmel, IN, United StatesHQ recorded Nov 5, 202611-5030 contacts →

Exact match

“Delivra, a Redbrick company, is a sophisticated email platform that designs custom solutions to help marketers and agencies automate highly personalized, event-driven campaigns…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202611-5024 contacts →

Exact match

“Empower your team to create, innovate, and grow with the Dyspatch Email Builder.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
16Exact matchPlano, TX, United StatesHQ recorded Nov 5, 202611-5023 contacts →

Exact match

“Helping brands scale to $5m in email sales every year.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17Exact matchPinedale, WY, United StatesHQ recorded Nov 5, 202611-5021 contacts →

Exact match

“GlockApps Software is a privately held company that offers multiple email marketing solutions to help businesses reach the inbox and solve email deliverability issues.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
18Exact matchNew Orleans, LA, United StatesHQ recorded Nov 5, 202611-5019 contacts →

Exact match

“Our newsletters engage your customers through curated content and help build relationships.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
19Exact matchBethesda, MD, United StatesHQ recorded Nov 5, 202651-20019 contacts →

Exact match

“Real Magnet is a leading marketing automation platform that helps businesses attract, engage and deliver better email, marketing, social and mobile campaigns.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
20Exact matchWilmington, DE, United StatesHQ recorded Nov 5, 202611-5018 contacts →

Exact match

“Email marketing is a powerful channel for small businesses to generate leads.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
21Exact matchWayne, PA, United StatesHQ recorded Nov 5, 202611-5017 contacts →

Exact match

“SocketLabs is an email service provider with a full suite of email delivery, management, and performance analysis tools.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
22Exact matchNew York, NY, United StatesHQ recorded Nov 5, 202611-5017 contacts →

Exact match

“Robly is a fast-growing remote start-up.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
23Exact matchSchneider, IN, United StatesHQ recorded Nov 5, 202611-5015 contacts →

Exact match

“Smarter, high-volume email delivery software for tech leaders & marketers.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
24Exact matchLandover, MD, United StatesHQ recorded Nov 5, 202611-5015 contacts →

Exact match

“Decision Software is an established marketing services and software provider located in Landover, Maryland, near Washington D.C.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
25Exact matchPleasanton, CA, United StatesHQ recorded Nov 5, 202611-5014 contacts →

Exact match

“Pinpointe’s cloud-based email marketing system empowers business (“B2B”) marketers to target and personalize their communications based on prospects behavior, interests and…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

Showing 25 of 243 open source email marketing software companies based in the United States

See the full list, filter by size, metro and specialty, and access 703 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Open source email marketing software companies based in the United States at a glance

As of Nov 5, 2026
25.5%Verified-email coverage
11.3Average contacts per company
11-50Median size (employees)
5.3%Largest-city concentration · Austin
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
105
11-50
99
51-200
25
201-500
8
501-1,000
1
1,001-5,000
3
10001+
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 243 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “open source email marketing software companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 703 professional contacts with verified work emails across the full matched dataset. 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 November 5, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “open source email marketing software companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many open source email marketing software companies are there based in the United States?

RevenueBase identified 243 company matches for open source email marketing software companies associated with the United States as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Icontact tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most open source email marketing software companies?

Austin leads with 13 company records, followed by New York (13) and Chicago (6).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 703 professional contacts with verified work emails tracked across these 243 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 5, 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 SmartSearch, 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.