According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), ESP1 is the email service provider (ESP) for 131 domains — 0.02% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
74.0% of its domains sit outside the top 100,000 — a long-tail footprint spread across smaller sites. Its single largest TLD is .com at 91.6% of its domains — a strong concentration across 8 TLDs overall. The service most often seen alongside it is Microsoft 365 (mailbox provider), on 35.9% of its domains.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 1 | 0.8% |
| Top 100,000 | 26 | 19.8% |
| Top 1,000,000 | 97 | 74.0% |
| Unranked | 7 | 5.3% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 120 | 91.6% | |
| .net | 2 | 1.5% | |
| .org | 2 | 1.5% | |
| .ca | 2 | 1.5% | |
| .co | 2 | 1.5% | |
| .co.uk | 1 | 0.8% | |
| .sc | 1 | 0.8% | |
| .eu | 1 | 0.8% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 131 domains.
| Type | Service | Domains | Share of ESP1 users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 47 | 35.9% |
| Mailbox | Google Workspace | 39 | 29.8% |
| Mailbox | Mimecast | 13 | 9.9% |
| Mailbox | Proofpoint | 10 | 7.6% |
| Mailbox | Self-Hosted | 4 | 3.1% |
| Mailbox | Unknown / Other | 3 | 2.3% |
| ESP | Amazon SES | 23 | 17.6% |
| ESP | Mailgun | 21 | 16.0% |
| ESP | SendGrid (Twilio) | 21 | 16.0% |
| ESP | Zendesk | 16 | 12.2% |
See the full ESP1 data page (KPI cards, trend, sample domains) →
131 domains in the Tranco top-1M use ESP1 as their email service provider (ESP) as of July 13, 2026 (0.02% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
ESP1 accounts for 0.02% 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.
ESP1's largest TLD is .com (91.6% of its domains); it appears across 8 TLDs in total.