1&1 IONOS email provider statistics and deliverability context

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According to Live Direct Marketing's daily Tranco top-1M scan (July 30, 2026), 1&1 IONOS is the mailbox provider for 4,244 domains — 0.64% of 667,152 domains with MX records. Over the last 30 days its share grew by 0.11 pp. Its strongest TLD is .com (43.0% of its domains). Detection: primary MX record (lowest preference).

Last updated from the 2026-07-30 DNS snapshot.

4,244domains
0.64%of domains with MX records
+0.11 ppshare, 30 days
110distinct TLDs
2026-07-30snapshot (updated daily)

What 1&1 IONOS represents in this dataset

1&1 IONOS — Europe's largest hosting brand, bundled mail for SMB.

Directory category: Hosting. The classification comes from primary MX record (lowest preference). It describes observed DNS infrastructure, not a commercial relationship and not the placement of any individual message.

What the 2026-07-30 snapshot shows about 1&1 IONOS

Across 110 distinct TLDs its top three are .com (43.0%), .de (21.3%), .co.uk (6.3%) — together 70.6% of the 4,244 domains, which makes the footprint narrow — three TLDs cover most of it, which is typical of a regional or single-market operator. The service most often observed on the same domains is Mailjet (Sinch) (ESP, 147 domains, 3.5% of them), followed by MailerSend (1.8%). Its share of domains with MX records moved +0.11 pp in 30 days, a change larger than list churn alone explains. Directly comparable by the same detection rule: Self-Hosted, Google Workspace, Microsoft 365. Ranking between them reflects what is published in DNS, not delivery quality or volume sent. All figures come from a single daily DNS snapshot (2026-07-30); a domain appears here when its published records match the primary MX record (lowest preference) rule, which is an infrastructure fact, not a commercial relationship.

Commonly used together with 1&1 IONOS

What else the same 4,244 domains use — cross-tabulated from the same daily snapshot (2026-07-30).

TypeServiceDomainsShare of 1&1 IONOS users
ESPMailjet (Sinch)1473.5%
ESPMailerSend771.8%
ESPBrevo (ex-Sendinblue)761.8%
ESPMailgun751.8%
ESPAmazon SES621.5%
ESPMailchimp451.1%
ESPMandrill441.0%
ESPZendesk400.9%
ESPSendGrid (Twilio)390.9%
ESPConstant Contact330.8%

TLD distribution (top 30 of 110)

com — 1,826 (43.0%)
de — 905 (21.3%)
co.uk — 266 (6.3%)
org — 222 (5.2%)
fr — 198 (4.7%)
net — 185 (4.4%)
es — 121 (2.9%)
eu — 54 (1.3%)
info — 50 (1.2%)
org.uk — 33 (0.8%)
ca — 29 (0.7%)
io — 28 (0.7%)
it — 25 (0.6%)
at — 23 (0.5%)
mx — 21 (0.5%)
online — 16 (0.4%)
app — 15 (0.4%)
uk — 13 (0.3%)
cloud — 13 (0.3%)
com.mx — 13 (0.3%)
shop — 11 (0.3%)
tv — 10 (0.2%)
ai — 8 (0.2%)
biz — 8 (0.2%)
co — 7 (0.2%)
me — 6 (0.1%)
club — 6 (0.1%)
in — 5 (0.1%)
ch — 5 (0.1%)
us — 5 (0.1%)

Frequently asked questions

How many domains use 1&1 IONOS?

4,244 domains in the Tranco top-1M use 1&1 IONOS as their mailbox provider as of July 30, 2026, according to Live Direct Marketing's daily DNS scan.

What is 1&1 IONOS's market share?

1&1 IONOS holds 0.64% of domains with MX records in the Tranco top-1M (snapshot of 2026-07-30). The number is recomputed every day.

Is 1&1 IONOS growing or declining?

1&1 IONOS's share grew by 0.11 percentage points over the last 30 days (as of July 30, 2026).

What are the biggest alternatives to 1&1 IONOS?

The largest mailbox providers in the same category by Tranco top-1M share are: Self-Hosted, Google Workspace, Microsoft 365, Unknown / Other, Generic / unmatched (mx*.*) (as of 2026-07-30).

Largest mailbox providers in this category

Self-Hosted (22.74%) · Google Workspace (21.79%) · Microsoft 365 (16.94%) · Unknown / Other (6.79%) · Generic / unmatched (mx*.*) (2.55%) · Proofpoint (1.93%) · Generic / unmatched (mail.*) (1.77%) · Yandex 360 (1.68%) · Cloudflare Email Routing (1.65%) · Mimecast (1.54%)

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Domain sample (top 100 by Tranco rank)

Showing 100 of 4,244 domains.