ESP1 email provider statistics and deliverability context
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According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), ESP1 is the email service provider (ESP) for 130 domains — 0.02% of 637,420 SPF-publishing domains. Its strongest TLD is .com (92.3% of its domains). Detection: include: mechanisms in the SPF record.
Last updated from the 2026-09-24 DNS snapshot.
What ESP1 represents in this dataset
ESP1 — Korean email service provider.
Directory category: Esp. The classification comes from include: mechanisms in the SPF record. It describes observed DNS infrastructure, not a commercial relationship and not the placement of any individual message.
What the 2026-09-24 snapshot shows about ESP1
Across 8 distinct TLDs its top three are .com (92.3%), .co (1.5%), .ca (1.5%) — together 95.4% of the 130 domains, which makes the footprint narrow — three TLDs cover most of it, which is typical of a regional or single-market operator. The service most often observed on the same domains is Microsoft 365 (Mailbox, 46 domains, 35.4% of them), followed by Google Workspace (31.5%). Directly comparable by the same detection rule: Amazon SES, SendGrid (Twilio), Mailgun. Ranking between them reflects what is published in DNS, not delivery quality or volume sent. All figures come from a single daily DNS snapshot (2026-09-24); a domain appears here when its published records match the include: mechanisms in the SPF record rule, which is an infrastructure fact, not a commercial relationship.
Commonly used together with ESP1
What else the same 130 domains use — cross-tabulated from the same daily snapshot (2026-09-24).
| Type | Service | Domains | Share of ESP1 users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 46 | 35.4% |
| Mailbox | Google Workspace | 41 | 31.5% |
| Mailbox | Mimecast | 10 | 7.7% |
| Mailbox | Proofpoint | 10 | 7.7% |
| Mailbox | Self-Hosted | 4 | 3.1% |
| Mailbox | Unknown / Other | 4 | 3.1% |
| ESP | Mailgun | 23 | 17.7% |
| ESP | Amazon SES | 22 | 16.9% |
| ESP | SendGrid (Twilio) | 21 | 16.2% |
| ESP | Zendesk | 14 | 10.8% |
TLD distribution (top 8 of 8)
Frequently asked questions
How many domains use ESP1?
130 domains in the Tranco top-1M use ESP1 as their email service provider (ESP) as of September 24, 2026, according to Live Direct Marketing's daily DNS scan.
What is ESP1's market share?
ESP1 holds 0.02% of SPF-publishing domains in the Tranco top-1M (snapshot of 2026-09-24). The number is recomputed every day.
What are the biggest alternatives to ESP1?
The largest email service provider (ESP)s in the same category by Tranco top-1M share are: Amazon SES, SendGrid (Twilio), Mailgun, Zendesk, Mailchimp (as of 2026-09-24).
Largest email service provider (ESP)s in this category
Amazon SES (6.23%) · SendGrid (Twilio) (4.68%) · Mailgun (4.01%) · Zendesk (3.77%) · Mailchimp (3.61%) · Mandrill (3.26%) · HubSpot (3.18%) · Salesforce (2.57%) · Mailjet (Sinch) (2.14%) · Cloudflare Email Routing (1.96%)
Domain sample (top 100 by Tranco rank)
Showing 100 of 130 domains.