Unknown / Other email provider statistics and deliverability context
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According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), Unknown / Other is the mailbox provider for 45,135 domains — 6.68% of 675,489 domains with MX records. Over the last 30 days its share declined by 0.13 pp, and -19.04 pp year-over-year. Its strongest TLD is .com (30.4% of its domains). Detection: primary MX record (lowest preference).
Last updated from the 2026-09-24 DNS snapshot.
What Unknown / Other represents in this dataset
MX targets that did not match any known pattern and don't follow the generic mail./mx./smtp. naming convention.
Directory category: Generic. The classification comes from primary MX record (lowest preference). 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 Unknown / Other
Across 510 distinct TLDs its top three are .com (30.4%), .de (7.9%), .net (5.8%) — together 44.0% of the 45,135 domains, which makes the footprint moderately concentrated, with a recognisable home market. The service most often observed on the same domains is Amazon SES (ESP, 1,559 domains, 3.5% of them), followed by SendGrid (Twilio) (2.2%). Its share of domains with MX records moved -0.13 pp in 30 days, a change larger than list churn alone explains. Year-over-year the share is -19.04 pp, so the 30-day move is consistent with the longer trend. Directly comparable by the same detection rule: Self-Hosted, Google Workspace, Microsoft 365. 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 primary MX record (lowest preference) rule, which is an infrastructure fact, not a commercial relationship.
Commonly used together with Unknown / Other
What else the same 45,135 domains use — cross-tabulated from the same daily snapshot (2026-09-24).
| Type | Service | Domains | Share of Unknown / Other users |
|---|---|---|---|
| ESP | Amazon SES | 1,559 | 3.5% |
| ESP | SendGrid (Twilio) | 1,012 | 2.2% |
| ESP | Mailchimp | 949 | 2.1% |
| ESP | Mailjet (Sinch) | 934 | 2.1% |
| ESP | Mailgun | 834 | 1.8% |
| ESP | Zendesk | 829 | 1.8% |
| ESP | Mandrill | 811 | 1.8% |
| ESP | Salesforce | 595 | 1.3% |
| ESP | Trend Micro Email Security | 591 | 1.3% |
| ESP | Brevo (ex-Sendinblue) | 501 | 1.1% |
TLD distribution (top 30 of 510)
Frequently asked questions
How many domains use Unknown / Other?
45,135 domains in the Tranco top-1M use Unknown / Other as their mailbox provider as of September 24, 2026, according to Live Direct Marketing's daily DNS scan.
What is Unknown / Other's market share?
Unknown / Other holds 6.68% of domains with MX records in the Tranco top-1M (snapshot of 2026-09-24). The number is recomputed every day.
Is Unknown / Other growing or declining?
Unknown / Other's share declined by 0.13 percentage points over the last 30 days (as of September 24, 2026).
What are the biggest alternatives to Unknown / Other?
The largest mailbox providers in the same category by Tranco top-1M share are: Self-Hosted, Google Workspace, Microsoft 365, Generic / unmatched (mx*.*), Generic / unmatched (mail.*) (as of 2026-09-24).
Largest mailbox providers in this category
Self-Hosted (22.56%) · Google Workspace (21.58%) · Microsoft 365 (17.03%) · Generic / unmatched (mx*.*) (2.53%) · Generic / unmatched (mail.*) (1.93%) · Proofpoint (1.86%) · Cloudflare Email Routing (1.76%) · Yandex 360 (1.67%) · Mimecast (1.47%) · Hostinger (1.12%)
Domain sample (top 100 by Tranco rank)
Showing 100 of 45,135 domains.