esp
According to Live Direct Marketing's daily Tranco top-1M scan (July 12, 2026), AuthSMTP is the email service provider (ESP) for 957 domains — 0.16% of 617,244 SPF-publishing domains. Its strongest TLD is .com (55.7% of its domains). Detection: include: mechanisms in the SPF record.
What else the same 957 domains use — cross-tabulated from the same daily snapshot (2026-07-12).
| Type | Service | Domains | Share of AuthSMTP users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 403 | 42.1% |
| Mailbox | Google Workspace | 207 | 21.6% |
| Mailbox | Self-Hosted | 63 | 6.6% |
| Mailbox | Mimecast | 56 | 5.9% |
| Mailbox | Unknown / Other | 53 | 5.5% |
| Mailbox | Proofpoint | 21 | 2.2% |
| ESP | Amazon SES | 114 | 11.9% |
| ESP | SendGrid (Twilio) | 113 | 11.8% |
| ESP | Zendesk | 96 | 10.0% |
| ESP | Mailchimp | 95 | 9.9% |
957 domains in the Tranco top-1M use AuthSMTP as their email service provider (ESP) as of July 12, 2026, according to Live Direct Marketing's daily DNS scan.
AuthSMTP holds 0.16% of SPF-publishing domains in the Tranco top-1M (snapshot of 2026-07-12). 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 2026-07-12).
Amazon SES (6.21%) · SendGrid (Twilio) (4.75%) · Mailgun (4.11%) · Zendesk (3.87%) · Mailchimp (3.69%) · Mandrill (3.36%) · HubSpot (3.18%) · Salesforce (2.62%) · Mailjet (Sinch) (2.13%) · Cloudflare Email Routing (1.80%)
Showing 100 of 957 domains.