According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), emBlue is the email service provider (ESP) for 529 domains — 0.09% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
emBlue is an email service provider that organisations use to send and manage outbound email campaigns and transactional messages. It integrates into email infrastructure as an SPF include mechanism, allowing mail systems to verify that sending servers authorised by emBlue are legitimate on behalf of the sender's domain.
emBlue's deployment pattern is concentrated among smaller and mid-market organisations rather than enterprise-scale senders, with presence across multiple international TLDs and .com predominantly represented. Its frequent co-appearance with Microsoft 365 in sender configurations suggests it is often deployed alongside Microsoft's platform, which is relevant to email deliverability because it reflects a specific infrastructure profile that receiving mail systems recognise and evaluate for sender reputation and trust.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 8 | 1.5% |
| Top 100,000 | 86 | 16.3% |
| Top 1,000,000 | 388 | 73.3% |
| Unranked | 47 | 8.9% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 142 | 26.8% | |
| .com.ar | 121 | 22.9% | |
| .pe | 49 | 9.3% | |
| .cl | 45 | 8.5% | |
| .ar | 42 | 7.9% | |
| .com.pe | 20 | 3.8% | |
| .co | 19 | 3.6% | |
| .com.co | 18 | 3.4% | |
| .uy | 15 | 2.8% | |
| .com.br | 14 | 2.6% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 529 domains.
| Type | Service | Domains | Share of emBlue users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 199 | 37.6% |
| Mailbox | Google Workspace | 165 | 31.2% |
| Mailbox | Self-Hosted | 63 | 11.9% |
| Mailbox | Unknown / Other | 24 | 4.5% |
| Mailbox | Trend Micro | 16 | 3.0% |
| Mailbox | Generic / unmatched (mx*.*) | 9 | 1.7% |
| ESP | Amazon SES | 82 | 15.5% |
| ESP | Mandrill | 55 | 10.4% |
| ESP | Zendesk | 49 | 9.3% |
| ESP | SendGrid (Twilio) | 49 | 9.3% |
emBlue appears in SPF records as an authorisation mechanism—when a domain includes emBlue in its SPF policy, it is explicitly authorising emBlue's servers to send email on its behalf. Because emBlue is prevalent in the long tail of the ESP market rather than among tier-one sending platforms, its presence in a sender's SPF record signals a particular infrastructure choice and often indicates a hybrid environment where the organisation also runs Microsoft 365. Receiving mail systems interpret these infrastructure signals differently, and understanding emBlue's role in your own configuration is important for accurate deliverability assessment.
See the full emBlue data page (KPI cards, trend, sample domains) →
emBlue is prevalent among smaller and mid-market senders, not the largest enterprises, so it is less universally recognised than top-tier ESPs; however, you should account for it in testing if your organisation uses it or if you are evaluating infrastructure that combines Microsoft 365 with additional sending platforms.
529 domains in the Tranco top-1M use emBlue as their email service provider (ESP) as of July 13, 2026 (0.09% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
emBlue accounts for 0.09% 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.
emBlue's largest TLD is .com (26.8% of its domains); it appears across 33 TLDs in total.