According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Selzy is the email service provider (ESP) for 185 domains — 0.03% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Selzy is an email service provider that authorises and delivers email on behalf of organisations. The service is visible across the email landscape through the SPF include mechanisms in DNS records that authorise mail relayed through Selzy, which is why Selzy appears in the technical infrastructure of many sending domains.
Selzy's footprint is concentrated in the long tail of smaller and mid-market organisations rather than amongst the world's largest brands. Its adoption spans international domains with notable presence in .com; it frequently appears alongside Google Workspace in SPF records, indicating it serves as part of the layered email stack that many organisations depend on. For anyone assessing email security or deliverability, Selzy represents a widely distributed third-party email relay provider rather than an outlier.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 3 | 1.6% |
| Top 100,000 | 17 | 9.2% |
| Top 1,000,000 | 141 | 76.2% |
| Unranked | 24 | 13.0% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 68 | 36.8% | |
| .ua | 20 | 10.8% | |
| .kz | 15 | 8.1% | |
| .com.ua | 12 | 6.5% | |
| .com.br | 8 | 4.3% | |
| .io | 6 | 3.2% | |
| .net | 6 | 3.2% | |
| .org | 4 | 2.2% | |
| .es | 3 | 1.6% | |
| .ru | 2 | 1.1% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 185 domains.
| Type | Service | Domains | Share of Selzy users |
|---|---|---|---|
| Mailbox | Google Workspace | 79 | 42.7% |
| Mailbox | Self-Hosted | 36 | 19.5% |
| Mailbox | Microsoft 365 | 31 | 16.8% |
| Mailbox | Yandex 360 | 9 | 4.9% |
| Mailbox | Ukraine.com.ua hosting | 7 | 3.8% |
| Mailbox | Unknown / Other | 5 | 2.7% |
| ESP | Unisender (RU) | 25 | 13.5% |
| ESP | Amazon SES | 23 | 12.4% |
| ESP | SendPulse | 21 | 11.4% |
| ESP | eSputnik (UA) | 17 | 9.2% |
Selzy's presence in email infrastructure is grounded in SPF (Sender Policy Framework) alignment. When an organisation uses Selzy, its SPF record explicitly authorises Selzy's mail servers to send email on the domain's behalf through an include mechanism. This alignment is critical to email deliverability: receiving systems evaluate whether mail claiming to come from a domain is actually authorised by that domain, and SPF provides that authorisation signal. Mail relayed through an SPF-aligned provider like Selzy carries stronger authentication markers than unauthorised mail, though receiving ISPs also consider the provider's operational history and reputation when making filtering decisions.
See the full Selzy data page (KPI cards, trend, sample domains) →
Selzy is an email service provider used by organisations to send email. When a domain uses Selzy, that domain's SPF record includes Selzy's servers as authorised senders, which is why Selzy appears frequently in SPF records across the web.
185 domains in the Tranco top-1M use Selzy as their email service provider (ESP) as of July 13, 2026 (0.03% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Selzy accounts for 0.03% 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.
Selzy's largest TLD is .com (36.8% of its domains); it appears across 44 TLDs in total.