Companies Using Fastmail

I analysed Fastmail against our September 2026 crawl, and the number needs one sentence of definition before anything else. We count a domain when its MX record, the DNS entry that tells other servers where to deliver its email, points at Fastmail's mail servers under messagingengine.com. On that basis 24,020 domains receive their email through Fastmail, and 11,163 of them match a company record. Every size, industry and country figure below describes those matched companies.

Why an MX count is worth trusting

An MX record is live routing. If it points at Fastmail, Fastmail is handling that mail today, and a company that leaves changes it the same day. We checked 80 random Fastmail domains against live DNS: 79 still routed to Fastmail, and the one that didn't had expired. Of 149 domains at the top of the list, 145 still did. 66 of the 80 served a live website and 8 a near-empty personal page; one showed a placeholder and one had no site at all.

The count has limits. The record carries no account number, so one account running five domains counts five times, and a family domain counts the same as a firm's. The website on each domain is hosted wherever the owner chose; only the mail is Fastmail's.

Sales signal: treat this as a list of domains with a paid, deliberate mail setup. Fastmail has taken no free sign-ups since 2012, so each of these domains is a mail setup someone chose and pays for.

The count over time

The chart reads 18,476 in June 2026, 22,510 in July, 22,797 in August and 24,020 in September. The June to July step comes from our side, not from adoption: the set of domains we crawl turns over every month, with dead sites dropping out and new ones added, and our coverage widens. Only 8.2% of today's domains were first seen in August or September. 492 domains have dropped Fastmail since we began tracking in March 2026, and because MX clears itself, those are real departures.

"An MX record is about as honest as detection gets. Fastmail either receives the mail or it doesn't, and 79 of 80 domains we checked by hand still did." - Emma Davies, Data Analyst at TechnologyChecker.io

Sales signal: use the September figure and the monthly movers, not the June to July slope. The base is stable, which makes the switching data below easier to read.

Who the customers are

87.42% of matched companies with a known size employ 1 to 10 people and 10.29% employ 11 to 50. Only 22 have more than 1,000 employees, Qmax in Houston among them. The founding years lean to the 2010s (43.97%), and 32.8% of dated companies predate 2010. Titan Email, which many hosts bundle with a website plan, shows the opposite shape: 42.28% of its matched companies were founded in the 2020s. That fits a mailbox people pick deliberately rather than one that arrives with a new website.

The named list is broader than that core suggests. Chicken of the Sea, the International Livestock Research Institute in Nairobi, Woodfibre LNG in British Columbia and AMETEK's ORTEC unit in Oak Ridge all route their domain's mail to Fastmail. Every name on this page comes from DNS, rechecked on 26 September 2026.

Sales signal: these are owner-operators who pay for tools they picked themselves. Pitch on control and privacy, not on scale.

Industries and countries

Software Development leads at 12.13%, then IT Services (7.77%) and Technology, Information and Internet (7.4%). With Information Technology & Services, roughly three in ten matched companies build or run technology. Advertising (3.04%), consulting (3.02%) and design studios (2.59%) follow.

The United States has 4,055 matched companies, the United Kingdom 1,629 and Australia 800, ahead of Canada's 480. Fastmail was founded in Melbourne in 1999 and still runs from there, and the Australian count reflects it. Six English-speaking markets hold 7,151 of the 9,643 matched companies with a known country. The Netherlands (379) and Germany (306) lead continental Europe.

Sales signal: English-language outreach covers most of this list, and Australia deserves its own segment rather than a line in an APAC bucket.

Where Fastmail's new domains come from

Since March 2026, 226 domains moved their MX from Google Workspace to Fastmail (93 in the last 30 days) and 96 from Microsoft 365 (37 in the last 30 days). Only 23 went from Fastmail to Google Workspace and 31 to Microsoft 365.

Small numbers need a base rate, so here is ours. 335 domains ran both Google Workspace and Fastmail at some point. If they had left Google at Google's usual rate across our crawl, about 5 would have gone. 226 did. For Microsoft 365 the same test expects about 2 of 169, and 96 moved. Against suites of nearly four million domains each, these flows are tiny. For Fastmail, 226 is close to 1% of its base.

We don't publish the Proton Mail rows. 52 domains moved from Proton Mail to Fastmail and 35 the other way, and two thirds of the domains that ever showed both still show both, so neither side is winning a clear switch.

"Fastmail's switching runs one way. For every domain that left it for Google Workspace, nearly ten came across from Google." - Emma Davies, Data Analyst at TechnologyChecker.io

Sales signal: the recent movers are the warmest leads on this page. A domain that just moved its mail from Google Workspace to Fastmail may have given up Drive and Docs with it, and may be shopping for replacements.

The stack around the mailbox

Across the 24,402 domains where Fastmail is live, Cloudflare sits in front of 46.25%. Developer hosts are common: Netlify on 4.81%, Vercel on 4.36% and GitHub Pages on 3.81%. Netlify reaches only 0.41% of Titan Email domains, which shows how different the two mail bases are. WordPress is on 19.08%. Google Analytics appears on 33.06%, with Plausible on 3.43% and Umami on 1.71%.

Sales signal: privacy-first and developer-friendly tools fit this base. A company that runs Plausible next to Fastmail has already said what it values.

What reviewers say

G2 lists Fastmail at 4.2 out of 5, but from only 17 reviews on 26 September 2026, too few for G2 to produce a pros and cons summary, so this page carries no review block. The busier discussion is on Reddit and Hacker News, where threads about leaving Google Workspace for Fastmail rank for "fastmail vs google workspace". Our data can't say why any one domain switched. It can say that the switches happen, and in which direction.

Sales signal: treat the switching counts, not star ratings, as the evidence when you pitch a Fastmail user.

Key takeaways

1. 24,020 domains receive email through Fastmail; 79 of 80 sampled still did when we checked.

2. 87.42% of matched companies with a known size employ 10 people or fewer.

3. Six English-speaking markets hold 7,151 of 9,643 matched companies with a country, and Australia is third.

4. 226 domains moved from Google Workspace and 96 from Microsoft 365 since March 2026, against 23 and 31 the other way.

5. Cloudflare on 46.25% and developer hosts on several percent each mark a technical base.

How to use this list

Start with the recent movers from Google Workspace and Microsoft 365, then filter on 1 to 50 employees in the US, UK and Australia. For the full list of 24,020 Fastmail domains with company, size and stack data, explore TechnologyChecker.io.