esp
According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Rule is the email service provider (ESP) for 152 domains — 0.02% of 617,702 SPF-publishing domains. Its strongest TLD is .se (55.3% of its domains). Detection: include: mechanisms in the SPF record.
What else the same 152 domains use — cross-tabulated from the same daily snapshot (2026-07-13).
| Type | Service | Domains | Share of Rule users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 94 | 61.8% |
| Mailbox | Google Workspace | 31 | 20.4% |
| Mailbox | Unknown / Other | 12 | 7.9% |
| Mailbox | Generic / unmatched (mx*.*) | 5 | 3.3% |
| Mailbox | Hornetsecurity | 3 | 2.0% |
| Mailbox | Generic / unmatched (mail.*) | 1 | 0.7% |
| ESP | Zendesk | 29 | 19.1% |
| ESP | Mandrill | 27 | 17.8% |
| ESP | Amazon SES | 27 | 17.8% |
| ESP | SendGrid (Twilio) | 22 | 14.5% |
152 domains in the Tranco top-1M use Rule as their email service provider (ESP) as of July 13, 2026, according to Live Direct Marketing's daily DNS scan.
Rule holds 0.02% of SPF-publishing domains in the Tranco top-1M (snapshot of 2026-07-13). The number is recomputed every day.
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 2026-07-13).
Amazon SES (6.21%) · SendGrid (Twilio) (4.76%) · Mailgun (4.11%) · Zendesk (3.86%) · Mailchimp (3.69%) · Mandrill (3.36%) · HubSpot (3.18%) · Salesforce (2.62%) · Mailjet (Sinch) (2.13%) · Cloudflare Email Routing (1.80%)
Showing 100 of 152 domains.