According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), InterNetX SMTP is the email service provider (ESP) for 295 domains — 0.05% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
InterNetX SMTP is the outbound mail infrastructure operated by InterNetX, a German domain registrar and web hosting provider. It serves customers who manage their domains and email through InterNetX's hosting platform.
The service has a distinctly long-tail footprint, appearing most often on smaller and mid-market sites rather than large-scale enterprises, with particularly strong presence on German-language domains and .de registrations. Its frequent co-occurrence with Microsoft 365 in SPF records suggests many senders combine InterNetX's hosted email with Microsoft's cloud services, creating mixed authentication stacks.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 27 | 9.2% |
| Top 1,000,000 | 253 | 85.8% |
| Unranked | 15 | 5.1% |
| TLD | Domains | Share | |
|---|---|---|---|
| .de | 129 | 43.7% | |
| .com | 74 | 25.1% | |
| .fr | 18 | 6.1% | |
| .net | 10 | 3.4% | |
| .at | 8 | 2.7% | |
| .org | 6 | 2.0% | |
| .ch | 6 | 2.0% | |
| .eu | 5 | 1.7% | |
| .hu | 3 | 1.0% | |
| .nl | 3 | 1.0% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 295 domains.
| Type | Service | Domains | Share of InterNetX SMTP users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 95 | 32.2% |
| Mailbox | Self-Hosted | 52 | 17.6% |
| Mailbox | Generic / unmatched (mx*.*) | 44 | 14.9% |
| Mailbox | Unknown / Other | 29 | 9.8% |
| Mailbox | Google Workspace | 26 | 8.8% |
| Mailbox | Hornetsecurity | 6 | 2.0% |
| ESP | Mailjet (Sinch) | 31 | 10.5% |
| ESP | emailsys (artegic, DE) | 27 | 9.2% |
| ESP | Brevo (ex-Sendinblue) | 18 | 6.1% |
| ESP | HubSpot | 16 | 5.4% |
InterNetX SMTP typically appears as an SPF include mechanism in the DNS records of domains hosted on InterNetX's platform, providing a direct link between the sender's mail infrastructure and their domain registration provider. For deliverability professionals and receiving systems, this pattern reliably signals that the sender uses their registrar's email service rather than a dedicated third-party ESP. Understanding this coupling is useful when assessing authentication posture and reputation: issues or changes in InterNetX's mail infrastructure can propagate directly to any sender relying on it.
See the full InterNetX SMTP data page (KPI cards, trend, sample domains) →
InterNetX SMTP is the mail service run by InterNetX, a domain registrar and hosting provider, primarily for customers who manage their domains through their platform. There is no general need to test against it specifically; rather, you may encounter it when auditing deliverability for senders whose domains are registered or hosted with InterNetX.
295 domains in the Tranco top-1M use InterNetX SMTP as their email service provider (ESP) as of July 13, 2026 (0.05% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
InterNetX SMTP accounts for 0.05% 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.
InterNetX SMTP's largest TLD is .de (43.7% of its domains); it appears across 33 TLDs in total.