Seznam.cz (Czech) mailbox provider
According to Live Direct Marketing's daily Tranco top-1M scan (September 20, 2026), Seznam.cz (Czech) is the mailbox provider for 339 domains — 0.05% of 676,114 domains with MX records. Detection method: primary MX record (lowest preference).
Key facts
- 339 domains in the Tranco top-1M use Seznam.cz (Czech) (0.05% of domains with MX records).
- Snapshot date: 2026-09-20 — recomputed every day.
- Strongest TLD: .cz (68.4% of its domains).
- Region skew: Czechia.
- Most co-used service: Mailchimp.
- Directory category: mailbox provider.
Why Seznam.cz (Czech) appears in this category
Czech consumer portal + mail, dominant in CZ.
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.
Seznam.cz is a Czech regional email service provider serving as a mailbox destination for users across the Czech Republic. It appears in email infrastructure as a primary MX record across websites in the .cz domain, forming part of the regional Central European email ecosystem.
Its presence in the Tranco top-1M list shows concentration within smaller regional sites rather than globally prominent brands, and it is regularly encountered alongside Mailchimp in email infrastructure data. This distribution indicates Seznam.cz receives email traffic from Czech-focused senders and regional bulk-mail campaigns, making it a consideration for anyone optimising deliverability to Czech audiences.
Where Seznam.cz (Czech) sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 1 | 0.3% |
| Top 10,000 | 6 | 1.8% |
| Top 100,000 | 26 | 7.7% |
| Top 1,000,000 | 304 | 89.7% |
| Unranked | 2 | 0.6% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .cz | 232 | 68.4% | |
| .com | 30 | 8.8% | |
| .eu | 18 | 5.3% | |
| .sk | 16 | 4.7% | |
| .net | 5 | 1.5% | |
| .hu | 4 | 1.2% | |
| .org | 4 | 1.2% | |
| .si | 3 | 0.9% | |
| .de | 3 | 0.9% | |
| .info | 3 | 0.9% |
What Seznam.cz (Czech) users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 339 domains.
| Type | Service | Domains | Share of Seznam.cz (Czech) users |
|---|---|---|---|
| ESP | Mailchimp | 21 | 6.2% |
| ESP | Heureka Mailing (CZ) | 19 | 5.6% |
| ESP | SmartEmailing | 16 | 4.7% |
| ESP | Mailgun | 11 | 3.2% |
| ESP | SparkPost | 10 | 2.9% |
| ESP | Amazon SES | 7 | 2.1% |
| ESP | Mailkit | 4 | 1.2% |
| ESP | SendGrid (Twilio) | 3 | 0.9% |
| ESP | MailerLite | 2 | 0.6% |
| ESP | MailerSend | 2 | 0.6% |
Regional relevance and testing scope for Czech market senders
Because Seznam.cz appears concentrated in the .cz mailbox space and smaller regional sites, it becomes a deliverability priority for campaigns aimed at Czech recipients but may warrant lower priority for senders with purely global scope. Its regular co-occurrence with Mailchimp in infrastructure data suggests it handles substantial volumes of regional bulk mail, making inbox placement testing there particularly relevant for Mailchimp users targeting Czech markets.
See the full Seznam.cz (Czech) data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Should I test email deliverability against Seznam.cz when optimising for Czech recipients?
Yes — it is a major mailbox provider in the Czech Republic and a regular destination for Czech-targeted email. Senders without a Czech or Central European audience may safely deprioritise it in favour of larger international providers.
How many domains use Seznam.cz (Czech)?
339 domains in the Tranco top-1M use Seznam.cz (Czech) as their mailbox provider as of September 20, 2026 (0.05% of domains with MX records), according to Live Direct Marketing's daily DNS scan.
Is Seznam.cz (Czech) common enough to affect email deliverability testing?
Seznam.cz (Czech) accounts for 0.05% 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 Seznam.cz (Czech) most?
Seznam.cz (Czech)'s largest TLD is .cz (68.4% of its domains); it appears across 26 TLDs in total.