United Domains (DE) mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), United Domains (DE) is the mailbox provider for 379 domains — 0.06% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

United Domains is a German domain registrar and web hosting provider that offers email hosting services to its customers. The company maintains a substantial presence in the European market, particularly in the .de space, and serves thousands of smaller and mid-market organisations across the continent.

In the email landscape, United Domains appears as a long-tail mailbox provider—common on smaller websites and regional businesses rather than global consumer or enterprise brands. The provider's presence clusters heavily around German-language sites and European TLDs, which means encountering mail from a United Domains address typically signals a regional or smaller-scale operation. For delivery professionals, this geographic concentration means United Domains operates its own mail infrastructure and authentication policies that may differ from globally distributed providers, so sender verification practices should remain consistent regardless of whether the recipient domain is hosted there.

Where United Domains (DE) sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00010.3%
Top 100,000154.0%
Top 1,000,00029076.5%
Unranked7319.3%

Top-level domain split

TLDDomainsShare
.de14137.2%
.com8321.9%
.net174.5%
.org164.2%
.eu102.6%
.io82.1%
.online82.1%
.fr61.6%
.info61.6%
.it51.3%

What United Domains (DE) users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 379 domains.

TypeServiceDomainsShare of United Domains (DE) users
ESPMailjet (Sinch)184.7%
ESPZendesk123.2%
ESPAmazon SES92.4%
ESPBrevo (ex-Sendinblue)92.4%
ESPMandrill30.8%
ESPMailgun30.8%
ESPMailchimp30.8%
ESPFreshdesk20.5%
ESPPostmark20.5%
ESPMailerSend20.5%

Regional mailbox clustering and authentication expectations

United Domains' customer base clusters geographically around Germany and continental Europe, which shapes authentication and reputation expectations for inbound mail. Whilst the provider maintains reasonable technical standards, its regional footprint means that sender authentication enforcement—SPF, DKIM, and DMARC—can vary by customer segment and local policy. Senders targeting European or German audiences should verify compliance with these authentication standards when routing mail to United Domains addresses, applying the same rigour as with any dedicated provider, but remain aware that acceptance policies may reflect regional deliverability norms rather than global best practices.

See the full United Domains (DE) data page (KPI cards, trend, sample domains) →

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Frequently asked questions

Should I test email delivery to United Domains when running campaigns?

If your recipient list includes a meaningful proportion of German-language or European small-business users, testing at least one sample to a United Domains address is prudent; otherwise, it is not typically a priority testing tier unless your audience skews heavily toward regional European organisations.

How many domains use United Domains (DE)?

379 domains in the Tranco top-1M use United Domains (DE) as their mailbox provider as of July 13, 2026 (0.06% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is United Domains (DE) common enough to affect email deliverability testing?

United Domains (DE) accounts for 0.06% 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 United Domains (DE) most?

United Domains (DE)'s largest TLD is .de (37.2% of its domains); it appears across 64 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%)