According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Heureka Mailing (CZ) is the email service provider (ESP) for 270 domains — 0.04% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Heureka Mailing is an email marketing service operated by Heureka, a Czech e-commerce and price-comparison platform. It provides campaign sending and list-management tools to smaller online retailers and service providers throughout Central Europe.
The service's email footprint is concentrated within Czech domains (.cz) and frequently appears alongside Microsoft 365 in SPF configurations, which indicates it serves as a supplementary sending channel for organisations that use Microsoft 365 for general business mail.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 21 | 7.8% |
| Top 1,000,000 | 208 | 77.0% |
| Unranked | 41 | 15.2% |
| TLD | Domains | Share | |
|---|---|---|---|
| .cz | 166 | 61.5% | |
| .sk | 49 | 18.1% | |
| .com | 8 | 3.0% | |
| .hu | 5 | 1.9% | |
| .eu | 5 | 1.9% | |
| .pl | 4 | 1.5% | |
| .gr | 3 | 1.1% | |
| .shop | 3 | 1.1% | |
| .de | 2 | 0.7% | |
| .hr | 2 | 0.7% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 270 domains.
| Type | Service | Domains | Share of Heureka Mailing (CZ) users |
|---|---|---|---|
| Mailbox | Google Workspace | 61 | 22.6% |
| Mailbox | Microsoft 365 | 59 | 21.9% |
| Mailbox | Self-Hosted | 32 | 11.9% |
| Mailbox | Unknown / Other | 26 | 9.6% |
| Mailbox | Generic / unmatched (mail.*) | 19 | 7.0% |
| Mailbox | vshosting (CZ) | 17 | 6.3% |
| ESP | Amazon SES | 30 | 11.1% |
| ESP | SparkPost | 25 | 9.3% |
| ESP | Mandrill | 25 | 9.3% |
| ESP | Mailgun | 23 | 8.5% |
Heureka Mailing often appears in SPF records together with Microsoft 365, particularly amongst smaller Czech organisations. This co-residence can contribute to SPF string complexity; administrators adding Heureka Mailing's include mechanism should verify that the combined record remains within DNS lookup limits and does not trigger SPF flattening issues when multiple includes are stacked.
See the full Heureka Mailing (CZ) data page (KPI cards, trend, sample domains) →
It indicates your organisation sends email through Heureka Mailing's service, typically for bulk campaigns. Its presence in your SPF record is expected if you use their platform; verify that the combined record with other includes (such as Microsoft 365) does not exceed DNS lookup limits.
270 domains in the Tranco top-1M use Heureka Mailing (CZ) as their email service provider (ESP) as of July 13, 2026 (0.04% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Heureka Mailing (CZ) accounts for 0.04% of SPF-publishing domains 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.
Heureka Mailing (CZ)'s largest TLD is .cz (61.5% of its domains); it appears across 30 TLDs in total.