Companies Using Microsoft 365

I trust the figures on this page more than almost any others I work with, and the reason is dull. Nobody picks a mail provider on a whim, switching costs a weekend of somebody's life, and the decision usually outlasts the person who made it. So when these numbers move they mean something, and when they sit still that means something too.

One instrument, both vendors

Microsoft 365 delivers mail for 3,753,495 domains and Google Workspace for 3,628,529. That is 45.31% against 43.80% of a category holding 8,284,814 domains, a gap of 124,966 domains and 1.51 percentage points. The two of them hold 89.10% between them and everything else in the category adds to 902,790, about a quarter of Microsoft's own footprint.

The share number is not what makes this worth quoting. Vendor share figures for business email usually come from two press releases counting different things, one in seats and one in tenants, and comparing them is a category error dressed up as analysis. Here both sides are read the same way, off the domain's MX record. If you want the mechanics, we wrote up how these detections work. The short version: a mail exchange record is a public statement about where a domain's email goes, an organisation changes it the day it migrates, and it does not depend on whether a marketing page renders. Whatever else you argue about, Google Workspace and Microsoft 365 are on the same ruler here.

The match rate is the evidence

The reason I would call this a census rather than a sample is not the raw size. It is that 3,032,116 of the 3,753,495 domains resolve to a company record, 80.8%. On most technologies we publish it sits closer to sixty. The surface explains the difference: a domain that has gone to the trouble of publishing a business mail server is almost always a real organisation with a real name, not a parked domain, a template site or a redirect.

What that buys you is that the breakdowns further up the page are not a thin slice extrapolated outwards. Four fifths of the population carries a company record, so the industry, size, country and age charts describe most of the thing itself.

Four fifths of these domains resolve to a named company. That is not a sample of business email. That is business email, with a fifth of it out of focus.

A small business product with a Fortune 500 mailing list

The named list on this page runs Tata Sons, Cognizant, Wipro, Marriott, SAP, Bosch, Unilever, Vodafone and the United States Air Force. The distribution behind it runs the other way entirely. 58.97% of the 2,866,833 matched companies that report a headcount employ ten people or fewer, 84.93% employ 50 or fewer, and only 4,976 domains belong to companies above 10,000 staff, which is 0.17%.

The age chart says the same thing from another angle. 18.28% of these organisations were founded in the 2020s and 50.19% since 2010. A five-person firm founded in 2022 does not inherit a mail server from anyone; it buys a subscription in an afternoon. Construction leading the industry table at 5.98% is the same finding in a third form, because construction is simply where a great many small companies are.

One caution about the named list, and it applies to every profile we publish. It is ordered by LinkedIn following, not by anything to do with Microsoft. Ten of the 33 organisations named here carry an Indian company record, and India is 1.78% of the matched base and eleventh by country. Indian IT and banking groups have enormous LinkedIn audiences. Read the charts for the market and the table for the examples, never the other way round.

Europe outweighs the United States here

The United States leads on 949,013 matched companies, 31.3%, and the line underneath it is the one worth looking at twice. The ten European countries inside the top fifteen carry 1,068,009 companies between them, more than the United States on its own. The ordering is unusual in its own right: Australia (177,685) and the Netherlands (162,159) both come in ahead of Canada (142,215), and the Netherlands on its own carries more matched companies than France and Switzerland together.

I would not read that as Microsoft selling harder in Rotterdam. Mail is bought through resellers and managed service providers in most of Europe, and a reseller channel spreads a product into places a direct sales team never reaches. It also means the buying decision was frequently made by somebody other than the company in the row, which matters if you are trying to sell that company something adjacent.

Why there is no switching table here

Because I have not measured one on the current data, and inferring a corridor from churn is how you publish a migration that never happened. What the churn does support is a statement about stability. 43,456 domains have stopped routing mail to Microsoft 365 since mid-March, 1.16% of the live base, with 43,384 of those in the last 90 days and 21,522 in the last 30.

That is among the lowest turnover we see anywhere, and the reason is the surface as much as the product. A detection read off a rendered page comes and goes with a consent banner, a slow response or a redesign, and rates of that kind can run into the tens of percent without a single customer leaving. A DNS record either points at Microsoft or it does not.

A drop rate of 1.16% on a base this size is not loyalty data. It is a statement about the measurement: mail records change when companies change them, and almost never otherwise.

What the rest of the stack says

In a 120,000-domain sample of the base, nothing about these sites is Microsoft shaped. jQuery is on about 62%, WordPress on roughly 42%, Yoast SEO on about 20%, close to half the WordPress figure. Google Analytics at roughly 47% and Google Tag Manager at about 46% both sit above WordPress, so on a page about Microsoft's mail product the honest observation is that Google owns the measurement layer on these websites. GoDaddy at roughly 31% is the row that tells you most about the buyer: a domain bought at a registrar with hosting attached, which is where a ten-person firm's website lives.

Those percentages are shares of the sample rather than of all 3,753,495 domains, and I would not push them past the nearest whole number.

What to take from this

Microsoft 365 is first in business email on 45.31% against Google Workspace's 43.80%, a lead of 124,966 domains that either vendor's marketing could reasonably claim as a tie. The number worth arguing with is not the share, it is the unit: this is domains whose mail Microsoft delivers, not seats, not licences, and not organisations, since a group with twelve domains contributes twelve rows. An organisation on Microsoft 365 for Office applications while routing mail through somebody else does not appear on this page at all. TechnologyChecker.io resolves the count against 3,032,116 identified companies and refreshes it every month.