Company lists · Data refreshed September 2026
Top 12 Cold email infrastructure providers based in the United Kingdom
RevenueBase identified 38 cold email infrastructure providers headquartered in the United Kingdom as of September 2026 and tracks 196 professional contacts across them, including 54 with verified work emails and 6 with mobile numbers. London is the largest hub.
This list covers cold email infrastructure providers headquartered in the United Kingdom, 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 3, 2026.
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.
The 12 largest cold email infrastructure providers based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 30 contacts → | ||||
Partial evidence “Since 2013, mailercloud has expanded to become one of the largest and most extensive cloud-based email services, that resolves the task of reliably delivering emails on behalf of…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 2 | 29 contacts → | ||||
Partial evidence “Folderly is an all-in-one email deliverability platform to supercharge your email performance.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 3 | 28 contacts → | ||||
Indirect evidence “Eloquent operates a range of platforms across various secure data centres in the UK, all of which are connected to our network and serve as the delivery point for our services.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 4 | 8 contacts → | ||||
Partial evidence “We are MailXpertise, a global ESP (email service provider), specialists in made-to-measure email and SMS solutions for marketing professionals.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 5 | 6 contacts → | ||||
Indirect evidence “Most B2B service businesses don't have a pipeline problem.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 6 | 4 contacts → | ||||
Strong evidence “KumoMTA is the open-source email infrastructure for enterprises and high-volume senders who want control and continuity without the risk, volatility, or pricing shocks that come…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 7 | 3 contacts → | ||||
Partial evidence “About Us: At Mailyser, we are passionate about helping businesses and individuals maximize their email marketing potential.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 8 | 2 contacts → | ||||
Partial evidence “An Enterprise class email marketing platform, providing industry leading delivery rates.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 9 | 2 contacts → | ||||
Partial evidence “Helping Recruiters With Email Deliverability.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 10 | 2 contacts → | ||||
Partial evidence “Whether you need a single Email account for your small business or a Virtual DataCentre for your large enterprise, we have the experience and skills to provide you with trusted…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 11 | 1 contacts → | ||||
Partial evidence “InboxWizards help small to large email senders deliver their emails to the Inbox.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 12 | 1 contacts → | ||||
Partial evidence “Red Circle Digital will help you get the most from your email marketing.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: cold email infrastructure providers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names cold email infrastructure providers.
- Partial evidence
- Its own public description names part of cold email infrastructure providers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name cold email infrastructure providers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 12 of 38 cold email infrastructure providers based in the United Kingdom
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Cold email infrastructure providers based in the United Kingdom at a glance
As of Sep 3, 2026Companies by employee count
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 cold email infrastructure providers, 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.
- What qualifies
- Companies headquartered in the United Kingdom whose own description of what they do matches “cold email infrastructure providers”. 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 cold email infrastructure providers), 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 cold email infrastructure providers, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
- 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, 54 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 3, 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.
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 cold email infrastructure providers, 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 cold email infrastructure providers are there based in the United Kingdom?
RevenueBase identified 38 cold email infrastructure providers headquartered in the United Kingdom 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?
Mailercloud, headquartered in London, tops this list with the largest team on record.
Which city has the most cold email infrastructure providers?
London leads with 23 headquartered companies, followed by Cambridge (1) and Manchester (1).
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 54 verified decision-maker contacts tracked across these 38 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 3, 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.
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