Microsoft 365 US Gov email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 7, 2026), Microsoft 365 US Gov is the email service provider (ESP) for 264 domains — 0.04% of 632,414 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 264 domains in the Tranco top-1M use Microsoft 365 US Gov (0.04% of SPF-publishing domains).
- Snapshot date: 2026-09-07 — recomputed every day.
- Strongest TLD: .com (85.2% of its domains).
- Most co-used service: Microsoft 365 US Government.
- Directory category: email security gateway.
Why Microsoft 365 US Gov appears in this category
Microsoft 365 — US Government Community Cloud.
We classify it as a email security gateway from include: mechanisms in the SPF record matching a maintained provider rule. This is infrastructure attribution from public DNS, not evidence of a direct contract or exclusive use.
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 band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 4 | 1.5% |
| Top 100,000 | 20 | 7.6% |
| Top 1,000,000 | 238 | 90.2% |
| Unranked | 2 | 0.8% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 225 | 85.2% | |
| .org | 9 | 3.4% | |
| .us | 7 | 2.7% | |
| .gov | 7 | 2.7% | |
| .mil | 4 | 1.5% | |
| .edu | 3 | 1.1% | |
| .net | 2 | 0.8% | |
| .com.br | 2 | 0.8% | |
| .aero | 1 | 0.4% | |
| .space | 1 | 0.4% |
What Microsoft 365 US Gov users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 264 domains.
| Type | Service | Domains | Share of Microsoft 365 US Gov users |
|---|---|---|---|
| Mailbox | Microsoft 365 US Government | 206 | 78.0% |
| Mailbox | Unknown / Other | 26 | 9.8% |
| Mailbox | Microsoft 365 | 6 | 2.3% |
| Mailbox | Google Workspace | 6 | 2.3% |
| Mailbox | Self-Hosted | 6 | 2.3% |
| Mailbox | Proofpoint | 4 | 1.5% |
| ESP | Amazon SES | 23 | 8.7% |
| ESP | Salesforce | 23 | 8.7% |
| ESP | HubSpot | 12 | 4.5% |
| ESP | Mailgun | 11 | 4.2% |
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) →
Run a free inbox-placement test across Gmail, Outlook, Yahoo and more — see exactly where your mail lands and why.
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?
264 domains in the Tranco top-1M use Microsoft 365 US Gov as their email service provider (ESP) as of September 7, 2026 (0.04% 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 0.04% 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 (85.2% of its domains); it appears across 13 TLDs in total.