Microsoft 365 US Gov email service provider (ESP)

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Microsoft 365 US Gov is the email service provider (ESP) for 514 domains — 0.08% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.

Key facts

Microsoft 365 US Gov is Microsoft's cloud productivity platform tailored for United States government agencies and their contractors. It is operated by Microsoft and provides hosted email, collaboration, and office services under compliance frameworks specific to federal and state government requirements.

In email authentication data, Microsoft 365 US Gov SPF configurations appear predominantly among smaller-scale websites and commercial entities in the .com domain space, often alongside unidentified or mixed infrastructure. This pattern reflects its role as a supporting service for government-aligned commercial operations rather than a mainstream public-facing email platform.

Where Microsoft 365 US Gov sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00020.4%
Top 100,000265.1%
Top 1,000,00039877.4%
Unranked8817.1%

Top-level domain split

TLDDomainsShare
.com47492.2%
.org91.8%
.us81.6%
.gov71.4%
.mil40.8%
.net20.4%
.edu20.4%
.com.br20.4%
.aero10.2%
.dev10.2%

What Microsoft 365 US Gov users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 514 domains.

TypeServiceDomainsShare of Microsoft 365 US Gov users
MailboxMicrosoft 365 US Government45588.5%
MailboxUnknown / Other265.1%
MailboxSelf-Hosted81.6%
MailboxProofpoint61.2%
MailboxGoogle Workspace61.2%
MailboxMicrosoft 36551.0%
ESPSalesforce275.3%
ESPProofpoint265.1%
ESPAmazon SES214.1%
ESPHubSpot142.7%

Email Authentication in Government and Contractor Infrastructure

When Microsoft 365 US Gov appears in email authentication records alongside unidentified infrastructure, the deployment often reflects hybrid government-contractor networks where email originates from mixed sources. Senders targeting these recipients should verify that SPF includes for Microsoft 365 US Gov are properly qualified and that DKIM signing policies align with both commercial and government compliance frameworks.

See the full Microsoft 365 US Gov data page (KPI cards, trend, sample domains) →

Are your emails landing in spam?
Run a free inbox-placement test across Gmail, Outlook, Yahoo and more — see exactly where your mail lands and why.
Test inbox placement →

Frequently asked questions

What is Microsoft 365 US Gov and does it affect my email?

Microsoft 365 US Gov is Microsoft's government-exclusive cloud platform for United States agencies and contractors. It affects email only if you send to or receive from government organisations using it; mainstream commercial senders typically do not encounter it as a primary recipient platform.

How many domains use Microsoft 365 US Gov?

514 domains in the Tranco top-1M use Microsoft 365 US Gov as their email service provider (ESP) as of July 13, 2026 (0.08% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.

Is Microsoft 365 US Gov common enough to affect email deliverability testing?

Microsoft 365 US Gov accounts for 0.08% of SPF-publishing domains in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.

Which countries or TLDs use Microsoft 365 US Gov most?

Microsoft 365 US Gov's largest TLD is .com (92.2% of its domains); it appears across 14 TLDs in total.

Other email service provider (ESP)s

Amazon SES (6.21%)SendGrid (Twilio) (4.76%)Mailgun (4.11%)Zendesk (3.86%)Mailchimp (3.69%)Mandrill (3.36%)HubSpot (3.18%)Salesforce (2.62%)Mailjet (Sinch) (2.13%)Cloudflare Email Routing (1.80%)