Mailbox.org mailbox provider
According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), Mailbox.org is the mailbox provider for 384 domains — 0.06% of 675,489 domains with MX records. Detection method: primary MX record (lowest preference).
Key facts
- 384 domains in the Tranco top-1M use Mailbox.org (0.06% of domains with MX records).
- Snapshot date: 2026-09-24 — recomputed every day.
- Strongest TLD: .de (34.4% of its domains).
- Region skew: Germany.
- Most co-used service: Amazon SES.
- Directory category: mailbox provider.
Why Mailbox.org appears in this category
Berlin mailbox/groupware with strong GDPR posture.
We classify it as a mailbox provider from primary MX record (lowest preference) matching a maintained provider rule. This is infrastructure attribution from public DNS, not evidence of a direct contract or exclusive use.
Mailbox.org is a privacy-focused email provider operated by Mailbox.org GmbH, a German company. It serves individual users and small organisations across Europe, positioning itself around data protection and user autonomy rather than enterprise-scale delivery.
In the Tranco top-1M footprint, Mailbox.org appears predominantly in the long tail of smaller web properties rather than among the world's largest brands, with pronounced concentration in German-speaking markets. For senders, this means Mailbox.org addresses are less common in mainstream bulk-mail lists but concentrated in European and privacy-conscious segments; for deliverability professionals, understanding Mailbox.org's authentication and filtering practices matters mainly when serving regional or European-focused audiences.
Where Mailbox.org sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 4 | 1.0% |
| Top 100,000 | 40 | 10.4% |
| Top 1,000,000 | 337 | 87.8% |
| Unranked | 3 | 0.8% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .de | 132 | 34.4% | |
| .com | 81 | 21.1% | |
| .org | 35 | 9.1% | |
| .net | 33 | 8.6% | |
| .eu | 11 | 2.9% | |
| .nl | 8 | 2.1% | |
| .app | 7 | 1.8% | |
| .dev | 7 | 1.8% | |
| .io | 6 | 1.6% | |
| .fr | 4 | 1.0% |
What Mailbox.org users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 384 domains.
| Type | Service | Domains | Share of Mailbox.org users |
|---|---|---|---|
| ESP | Amazon SES | 25 | 6.5% |
| ESP | Constant Contact | 15 | 3.9% |
| ESP | Brevo (ex-Sendinblue) | 14 | 3.6% |
| ESP | Zendesk | 13 | 3.4% |
| ESP | Mailjet (Sinch) | 12 | 3.1% |
| ESP | Newsletter2Go (Brevo) | 6 | 1.6% |
| ESP | Mailchimp | 5 | 1.3% |
| ESP | Mailgun | 4 | 1.0% |
| ESP | Postmark | 3 | 0.8% |
| ESP | Scaleway TEM | 3 | 0.8% |
Regional footprint and sender reputation monitoring
Because Mailbox.org sits primarily in smaller web properties and German-language markets rather than among the largest global websites, sender reputation at Mailbox.org should be monitored as a distinct regional signal rather than rolled into global metrics. Organisations serving European or German-speaking audiences can expect regular exposure to Mailbox.org subscribers and should include the provider in their regional deliverability assessments; those focused on global bulk delivery can deprioritise it without material impact on reach.
See the full Mailbox.org data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Should I test my email delivery against Mailbox.org?
If your audience spans Europe or German-speaking regions, Mailbox.org is worth including in your regional test matrix; otherwise, its presence in the long tail of smaller websites means it can be deprioritised in global deliverability testing.
How many domains use Mailbox.org?
384 domains in the Tranco top-1M use Mailbox.org as their mailbox provider as of September 24, 2026 (0.06% of domains with MX records), according to Live Direct Marketing's daily DNS scan.
Is Mailbox.org common enough to affect email deliverability testing?
Mailbox.org accounts for 0.06% 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.
Which countries or TLDs use Mailbox.org most?
Mailbox.org's largest TLD is .de (34.4% of its domains); it appears across 49 TLDs in total.