mailbox
According to Live Direct Marketing's daily Tranco top-1M scan (July 26, 2026), Unknown / Other is the mailbox provider for 45,439 domains — 6.80% of 667,887 domains with MX records. Over the last 30 days its share declined by 1.07 pp, and -19.09 pp year-over-year. Its strongest TLD is .com (31.0% of its domains). Detection: primary MX record (lowest preference).
Last updated from the 2026-07-26 DNS snapshot.
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.
Across 523 distinct TLDs its top three are .com (31.0%), .de (7.1%), .net (5.8%) — together 44.0% of the 45,439 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, 1,576 domains, 3.5% of them), followed by SendGrid (Twilio) (2.4%). Its share of domains with MX records moved -1.07 pp in 30 days, a change larger than list churn alone explains. Year-over-year the share is -19.09 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 (2026-07-26); 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.
What else the same 45,439 domains use — cross-tabulated from the same daily snapshot (2026-07-26).
| Type | Service | Domains | Share of Unknown / Other users |
|---|---|---|---|
| ESP | Amazon SES | 1,576 | 3.5% |
| ESP | SendGrid (Twilio) | 1,108 | 2.4% |
| ESP | Mailchimp | 1,027 | 2.3% |
| ESP | Mailjet (Sinch) | 962 | 2.1% |
| ESP | Zendesk | 897 | 2.0% |
| ESP | Mandrill | 892 | 2.0% |
| ESP | Mailgun | 878 | 1.9% |
| ESP | Salesforce | 647 | 1.4% |
| ESP | Trend Micro Email Security | 592 | 1.3% |
| ESP | Brevo (ex-Sendinblue) | 511 | 1.1% |
45,439 domains in the Tranco top-1M use Unknown / Other as their mailbox provider as of July 26, 2026, according to Live Direct Marketing's daily DNS scan.
Unknown / Other holds 6.80% of domains with MX records in the Tranco top-1M (snapshot of 2026-07-26). The number is recomputed every day.
Unknown / Other's share declined by 1.07 percentage points over the last 30 days (as of July 26, 2026).
The largest mailbox providers in the same category by Tranco top-1M share are: Self-Hosted, Google Workspace, Microsoft 365, Generic / unmatched (mx*.*), Proofpoint (as of 2026-07-26).
Self-Hosted (22.75%) · Google Workspace (21.84%) · Microsoft 365 (16.92%) · Generic / unmatched (mx*.*) (2.54%) · Proofpoint (1.92%) · Generic / unmatched (mail.*) (1.77%) · Yandex 360 (1.68%) · Cloudflare Email Routing (1.63%) · Mimecast (1.53%) · Hostinger (1.15%)
Showing 100 of 45,439 domains.