Seznam.cz (Czech) mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Seznam.cz (Czech) is the mailbox provider for 293 domains — 0.04% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

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 bandDomainsShare of its base
Top 1,00010.3%
Top 10,00051.7%
Top 100,000248.2%
Top 1,000,00020871.0%
Unranked5518.8%

Top-level domain split

TLDDomainsShare
.cz20570.0%
.com299.9%
.eu175.8%
.sk113.8%
.net62.0%
.org31.0%
.pl31.0%
.hu20.7%
.hr20.7%
.ro10.3%

What Seznam.cz (Czech) users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 293 domains.

TypeServiceDomainsShare of Seznam.cz (Czech) users
ESPMailchimp165.5%
ESPHeureka Mailing (CZ)165.5%
ESPSmartEmailing155.1%
ESPMailgun124.1%
ESPSparkPost113.8%
ESPMailerSend51.7%
ESPMailkit41.4%
ESPMandrill20.7%
ESPAmazon SES20.7%
ESPBrevo (ex-Sendinblue)20.7%

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) →

Are your emails landing in spam?
Run a free inbox-placement test across Gmail, Outlook, Yahoo and more — see exactly where your mail lands and why.
Test inbox placement →

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)?

293 domains in the Tranco top-1M use Seznam.cz (Czech) as their mailbox provider as of July 13, 2026 (0.04% 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 0.04% 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 (70.0% of its domains); it appears across 24 TLDs in total.

Other mailbox providers

Self-Hosted (22.44%)Google Workspace (21.79%)Microsoft 365 (16.74%)Unknown / Other (7.54%)Generic / unmatched (mx*.*) (2.57%)Proofpoint (1.90%)Generic / unmatched (mail.*) (1.75%)Yandex 360 (1.64%)Cloudflare Email Routing (1.60%)Mimecast (1.52%)