GMX mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (September 18, 2026), GMX is the mailbox provider for 11 domains — 0.00% of 675,783 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

Why GMX appears in this category

United Internet consumer brand, popular in Germany/Austria.

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.

GMX is a mailbox provider and email infrastructure service with significant operational presence in European markets, particularly Germany. It hosts email for numerous organisations across the Tranco top-1 million list of high-traffic domains, serving a global audience with regional concentration in German-speaking regions.

GMX's footprint among well-known and enterprise-grade organisations means senders and recipients working with GMX-hosted email need to understand its infrastructure and filtering policies. For senders, reliable delivery to GMX depends on adhering to email authentication standards and maintaining sender reputation; for recipients, GMX's infrastructure influences their inbound filtering thresholds.

Where GMX sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00019.1%
Top 100,000763.6%
Top 1,000,000327.3%
Unranked00.0%

Top-level domain split

TLDDomainsShare
.de218.2%
.com218.2%
.net19.1%
.at19.1%
.ch19.1%
.co.uk19.1%
.es19.1%
.fr19.1%
.us19.1%

Authentication standards and sender filtering

GMX's prevalence among high-traffic and established organisations reflects the maturity of senders using its infrastructure. Email authentication (SPF, DKIM, DMARC) is industry standard across large mailbox providers and directly influences filtering decisions; senders targeting GMX-hosted domains should ensure their authentication records are properly configured and their sending infrastructure maintains a credible reputation.

See the full GMX data page (KPI cards, trend, sample domains) →

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Frequently asked questions

Does GMX filtering matter for my email programme?

GMX hosts mail for high-traffic and enterprise organisations with concentration in German-speaking markets. If your recipient list includes .de domains, organisations in European markets, or domains among the top-1 million websites, GMX inbox placement directly impacts your deliverability success.

How many domains use GMX?

11 domains in the Tranco top-1M use GMX as their mailbox provider as of September 18, 2026 (0.00% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is GMX common enough to affect email deliverability testing?

GMX accounts for 0.00% 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 GMX most?

GMX's largest TLD is .de (18.2% of its domains); it appears across 9 TLDs in total.

Other mailbox providers

Self-Hosted (22.49%)Google Workspace (21.62%)Microsoft 365 (17.01%)Unknown / Other (6.67%)Generic / unmatched (mx*.*) (2.54%)Generic / unmatched (mail.*) (1.94%)Proofpoint (1.86%)Cloudflare Email Routing (1.75%)Yandex 360 (1.63%)Mimecast (1.46%)