According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Runbox is the mailbox provider for 66 domains — 0.01% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).
Runbox is a mailbox provider used by smaller and mid-market organisations worldwide to receive email on their domains. It is distributed globally, with a concentration on the .com TLD and regional patterns tilted toward the United States and broader international markets.
For email senders, encountering Runbox as an MX record typically indicates an organisation that also uses Amazon SES for outbound mail. This send–receive split affects reputation signals and filtering logic, requiring senders to align their SES authentication (SPF, DKIM, DMARC) with the receiving side's expectations.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 15 | 22.7% |
| Top 1,000,000 | 40 | 60.6% |
| Unranked | 11 | 16.7% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 22 | 33.3% | |
| .net | 7 | 10.6% | |
| .org | 5 | 7.6% | |
| .io | 3 | 4.5% | |
| .de | 2 | 3.0% | |
| .gq | 2 | 3.0% | |
| .co | 1 | 1.5% | |
| .com.my | 1 | 1.5% | |
| .cc | 1 | 1.5% | |
| .fi | 1 | 1.5% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 66 domains.
| Type | Service | Domains | Share of Runbox users |
|---|---|---|---|
| ESP | Amazon SES | 4 | 6.1% |
| ESP | Mailchimp | 2 | 3.0% |
| ESP | HubSpot | 1 | 1.5% |
| ESP | Mailgun | 1 | 1.5% |
| ESP | Help Scout | 1 | 1.5% |
| ESP | SendGrid (Twilio) | 1 | 1.5% |
| ESP | SenderSRV | 1 | 1.5% |
| ESP | Postmark | 1 | 1.5% |
| ESP | Zendesk | 1 | 1.5% |
Organisations using Runbox for inbound mail commonly pair it with Amazon SES for outbound delivery, creating a pattern where sending and receiving infrastructure are separate. This divergence complicates reputation assessment, as filter heuristics may not consistently evaluate the same organisation across both paths. Senders targeting such organisations should verify their SES credentials are correct and trust anchors (SPF, DKIM, DMARC) are strong, since mail systems may apply heightened scrutiny when inbound and outbound infrastructure mismatch noticeably.
See the full Runbox data page (KPI cards, trend, sample domains) →
Runbox is the inbound mail server for that organisation, typically a smaller or mid-market business using managed email hosting, frequently paired with Amazon SES for sending outbound mail.
66 domains in the Tranco top-1M use Runbox as their mailbox provider as of July 13, 2026 (0.01% of domains with MX records), according to Live Direct Marketing's daily DNS scan.
Runbox accounts for 0.01% of domains with MX records in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.
Runbox's largest TLD is .com (33.3% of its domains); it appears across 31 TLDs in total.