Which email security gateway do companies use?
About one in 3 of the 499 business domains we measure route inbound mail through Proofpoint (33.9%). 42.9% sit behind any security gateway. 26.1% receive mail directly at Microsoft 365, 18.8% at Google Workspace, and 9.6% run their own mail server or one we do not recognise. Measured 2026-09-05 from public MX records.
What this measures, and what it does not
On each measurement, Emailchaser looks up the MX records of a fixed panel of 499 real business domains and classifies the host that receives their mail. On 2026-09-05, 499 of them resolved. There have been 10 measurements since 2026-08-10.
The classification stops at the first match. A domain whose MX points at Proofpoint is counted as Proofpoint even when Microsoft 365 or Google Workspace sits behind it, because the gateway is the software that reads the message first. The mailbox provider shares here are therefore the domains that receive mail directly, with nothing in front.
These are recipient domains, the kind a cold emailer writes to. This is not Emailchaser customer data and not sending data. It says what the companies you email have set up. It does not predict where your mail lands: that is judged against your own domain's records.
Gateways versus mailbox providers
The security gateways in the mix on 2026-09-05: Proofpoint 33.9%, Mimecast 4%. Together with the smaller ones they receive mail for 42.9% of measured domains.
Direct mailbox providers: Microsoft 365 26.1%, Google Workspace 18.8%. 9.6% of domains point their MX at their own servers or at a host we do not recognise, and 2.4% publish no MX record, so mail to them has nowhere obvious to go and usually bounces.
Of the same domains, 32 (6.4%) publish an MTA-STS policy, which asks sending servers to deliver to them over valid TLS only.
What a sender can take from it
A gateway applies its own rules on top of whatever the mailbox provider does. The one thing every gateway and every mailbox provider checks first is authentication: SPF, DKIM and DMARC alignment on the sending domain. Get that right before reading anything into the mix.
The second thing they all watch is bounces. A list that has not been verified produces dead addresses, and a domain that keeps hitting them loses reputation with every filter on this page. Verify before you send.
Every provider in the mix, with counts
| Who receives the mail | Kind | Domains | Share |
|---|---|---|---|
| Proofpoint | security gateway | 169 | 33.9% |
| Microsoft 365 | mailbox provider | 130 | 26.1% |
| Google Workspace | mailbox provider | 94 | 18.8% |
| Their own servers, or unknown | own mail server | 48 | 9.6% |
| Mimecast | security gateway | 20 | 4% |
| Cisco Secure Email | security gateway | 19 | 3.8% |
| Cannot receive email at all | no MX record | 12 | 2.4% |
| Trend Micro | security gateway | 5 | 1% |
| Barracuda | security gateway | 1 | 0.2% |
| Zoho Mail | mailbox provider | 1 | 0.2% |
Inbox Rules Index
Measured Saturday, 5 September 2026 across 499 real business domains, 10 measurements since 2026-08-10. On each measurement we look up the published email settings of the same 499 real companies, the kind you send cold email to. This is what they have set up, not a score on your own sending. It does not predict where your mail lands: that is judged against your own domain's records.
Whose spam filter your email meets
| Proofpoint | 33.9% | |
| Microsoft 365 | 26.1% | |
| Google Workspace | 18.8% | |
| Their own servers, or unknown | 9.6% | |
| Mimecast | 4% | |
| Cisco Secure Email | 3.8% |
Proofpoint screens about one in every 3 of these companies, more than any other filter. This is the software that reads your email before a person does. It says nothing about how any one of them treats your mail.
Which industries guard their name hardest (companies checked)
| Software (126) | 97.6% | |
| Finance (54) | 94.4% | |
| Services (28) | 92.9% | |
| Healthcare (47) | 89.4% | |
| Logistics (17) | 88.2% | |
| Retail (50) | 88% | |
| Travel (25) | 88% | |
| Energy (24) | 87.5% | |
| Media (26) | 84.6% | |
| Telecoms (30) | 80% | |
| Industrial (44) | 79.5% | |
| Schools and universities (28) | 57.1% |
Software guards its name hardest: 97.6% block mail faking their address. Schools and universities least, at 57.1%, a gap of 40.5 points. A high number means that industry runs email security tightly, so expect your own setup to be looked at more closely there.
The last 10 measurements
| Date | DMARC enforced | At p=reject | No DMARC | Strict SPF | Domains measured |
|---|---|---|---|---|---|
| 2026-09-05 | 88.4% | 70.3% | 1.2% | 43.1% | 499 |
| 2026-09-04 | 88.4% | 70.3% | 1.2% | 42.7% | 499 |
| 2026-09-03 | 88.4% | 70.3% | 1.2% | 42.7% | 499 |
| 2026-09-02 | 88.4% | 70.3% | 1.2% | 42.9% | 499 |
| 2026-09-01 | 88.4% | 70.3% | 1.2% | 42.9% | 499 |
| 2026-08-31 | 88.4% | 70.3% | 1.2% | 42.9% | 499 |
| 2026-08-28 | 88.4% | 70.3% | 1.2% | 42.7% | 499 |
| 2026-08-26 | 88.4% | 70.3% | 1.2% | 42.7% | 499 |
| 2026-08-15 | 88.1% | 70% | 1.2% | 42.9% | 497 |
| 2026-08-10 | 88% | 70.3% | 1.2% | 43.2% | 498 |
Measured by Emailchaser over public DNS, 10 measurements since 2026-08-10, on a fixed panel of 499 business domains. This measures the domains a sender emails. It is not Emailchaser customer sending data.
Download all measurements (JSON)Related questions
What is an email security gateway?
A filtering service that a company puts in front of its mailboxes by pointing its MX records at it. Proofpoint, Mimecast, Cisco Secure Email, Trend Micro and Barracuda are the ones this measurement recognises. Mail reaches the gateway first, and only what it passes goes on to Microsoft 365, Google Workspace or the company's own server.
Does a gateway in front of Microsoft 365 count as Microsoft 365?
No. The classification uses the first MX match, so a domain with Proofpoint in front of Microsoft 365 is counted as Proofpoint. The Microsoft 365 and Google Workspace shares are the domains that receive mail directly.
Where do these numbers come from?
DNS lookups of the MX records of the same fixed panel of 499 real business domains, 10 measurements since 2026-08-10. Every measurement, with counts, is published as JSON at https://www.emailchaser.com/api/inbox-rules-index.json under a CC BY 4.0 licence.
Does this tell me whether my email will be blocked?
No. It tells you what the recipients have set up. Whether a message is accepted is judged against the sender's own records and reputation, which this measurement does not look at.
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