According to Live Direct Marketing's daily Tranco top-1M scan (July 12, 2026), SMTP.BZ is the email service provider (ESP) for 719 domains — 0.12% of 617,244 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
SMTP.BZ is a Russian email service provider that offers SMTP relay and email infrastructure services, predominantly serving smaller organisations and businesses within Russian-speaking markets. The service is commonly found in SPF include mechanisms across the web, indicating its widespread use for outbound mail authorisation.
Its footprint is distinctly regional—concentrated in the .ru namespace and rarely seen among the world's largest brands, instead serving smaller and regionally focused sites. For senders, this reflects a deliberate choice of infrastructure tailored to regional compliance and local ISP relationships; for receivers, mail authorised via SMTP.BZ typically indicates a smaller or region-focused operation rather than a multinational enterprise.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 1 | 0.1% |
| Top 10,000 | 11 | 1.5% |
| Top 100,000 | 106 | 14.7% |
| Top 1,000,000 | 530 | 73.7% |
| Unranked | 71 | 9.9% |
| TLD | Domains | Share | |
|---|---|---|---|
| .ru | 404 | 56.2% | |
| .com | 113 | 15.7% | |
| .net | 24 | 3.3% | |
| .online | 17 | 2.4% | |
| .pro | 16 | 2.2% | |
| .su | 15 | 2.1% | |
| .io | 12 | 1.7% | |
| .org | 8 | 1.1% | |
| .by | 8 | 1.1% | |
| .cc | 8 | 1.1% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 719 domains.
| Type | Service | Domains | Share of SMTP.BZ users |
|---|---|---|---|
| Mailbox | Yandex 360 | 223 | 31.0% |
| Mailbox | Self-Hosted | 136 | 18.9% |
| Mailbox | Mail.ru for Business | 103 | 14.3% |
| Mailbox | Google Workspace | 69 | 9.6% |
| Mailbox | Unknown / Other | 22 | 3.1% |
| Mailbox | Timeweb (RU) | 19 | 2.6% |
| ESP | Unisender (RU) | 114 | 15.9% |
| ESP | SendPulse | 66 | 9.2% |
| ESP | Mindbox | 25 | 3.5% |
| ESP | UniSender | 24 | 3.3% |
SMTP.BZ's presence in Russian-speaking markets, particularly its frequent pairing with Yandex 360 in SPF records, reveals how smaller regional organisations often layer email providers to match local compliance and ISP realities. This co-occurrence in authentication records suggests SMTP.BZ typically handles specialist roles—transactional mail, operational alerts, or compliance-driven correspondence—rather than primary marketing channels. Recipients should interpret SMTP.BZ in SPF records as a signal of regional infrastructure choice, not as a reputation indicator.
See the full SMTP.BZ data page (KPI cards, trend, sample domains) →
SMTP.BZ is a Russian email service provider used by smaller organisations across Russian-speaking markets for outbound mail delivery. Its inclusion in an SPF record means that domain authorises SMTP.BZ's mail servers to send on its behalf, often for transactional or operational correspondence.
719 domains in the Tranco top-1M use SMTP.BZ as their email service provider (ESP) as of July 12, 2026 (0.12% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
SMTP.BZ accounts for 0.12% 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.
SMTP.BZ's largest TLD is .ru (56.2% of its domains); it appears across 62 TLDs in total.