According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Zoner (CZ) is the mailbox provider for 139 domains — 0.02% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).
Zoner is a Czech-based regional email service provider serving mailboxes primarily within Czechia. It operates as a smaller, locally-focused alternative to global providers, concentrated in the .cz domain ecosystem and oriented toward domestic Czech organisations and businesses.
When Zoner appears as a primary MX record across a website's mail infrastructure, it signals a smaller or regionally-rooted organisation rather than an enterprise with global deployment. For senders targeting Czech audiences, Zoner's presence is worth accounting for when the recipient base skews towards domestic Czech entities; it is frequently observed alongside Heureka Mailing, another Czech-operated mail service, suggesting common patterns in regional Czech infrastructure.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 12 | 8.6% |
| Top 1,000,000 | 105 | 75.5% |
| Unranked | 22 | 15.8% |
| TLD | Domains | Share | |
|---|---|---|---|
| .cz | 69 | 49.6% | |
| .com | 18 | 12.9% | |
| .sk | 15 | 10.8% | |
| .hu | 5 | 3.6% | |
| .de | 4 | 2.9% | |
| .pl | 3 | 2.2% | |
| .ro | 2 | 1.4% | |
| .es | 2 | 1.4% | |
| .fr | 2 | 1.4% | |
| .rs | 1 | 0.7% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 139 domains.
| Type | Service | Domains | Share of Zoner (CZ) users |
|---|---|---|---|
| ESP | Heureka Mailing (CZ) | 12 | 8.6% |
| ESP | SmartEmailing | 11 | 7.9% |
| ESP | Mailkit | 4 | 2.9% |
| ESP | SparkPost | 4 | 2.9% |
| ESP | Mailchimp | 3 | 2.2% |
| ESP | Mailjet (Sinch) | 2 | 1.4% |
| ESP | Amazon SES | 2 | 1.4% |
| ESP | Zendesk | 2 | 1.4% |
| ESP | Brevo (ex-Sendinblue) | 2 | 1.4% |
| ESP | Mailgun | 1 | 0.7% |
Because Zoner's footprint concentrates in the Czech market and the .cz domain space, inbox placement testing against Zoner is most relevant when your sending programme targets Czech recipients or Czech-registered domains. A deliverability assessment that aims to cover European regional providers should include Zoner, particularly for campaigns destined for smaller Czech organisations; however, if your audience is predominantly anglophone or non-Czech, Zoner may fall outside the core test matrix for your programme.
See the full Zoner (CZ) data page (KPI cards, trend, sample domains) →
If your recipients include Czech-based mailboxes or Czech organisations, Zoner is a relevant test case; otherwise, it is not critical to most international sending programmes.
139 domains in the Tranco top-1M use Zoner (CZ) as their mailbox provider as of July 13, 2026 (0.02% of domains with MX records), according to Live Direct Marketing's daily DNS scan.
Zoner (CZ) accounts for 0.02% 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.
Zoner (CZ)'s largest TLD is .cz (49.6% of its domains); it appears across 28 TLDs in total.