OpenSRS (Tucows) mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (September 10, 2026), OpenSRS (Tucows) is the mailbox provider for 1,811 domains — 0.27% of 667,099 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

Why OpenSRS (Tucows) appears in this category

Tucows wholesale mail platform for resellers.

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.

What the data shows

93.5% of its domains sit outside the top 100,000 — a long-tail footprint spread across smaller sites. Its single largest TLD is .com at 65.9% of its domains — a strong concentration across 97 TLDs overall. The service most often seen alongside it is Wild West Domains Forwarder (ESP), on 4.9% of its domains.

Where OpenSRS (Tucows) sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00010.1%
Top 10,00070.4%
Top 100,000673.7%
Top 1,000,0001,69393.5%
Unranked432.4%

Top-level domain split

TLDDomainsShare
.com1,19365.9%
.net1196.6%
.org784.3%
.shop402.2%
.ca392.2%
.store291.6%
.co.uk251.4%
.fr231.3%
.in211.2%
.de170.9%

What OpenSRS (Tucows) users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 1,811 domains.

TypeServiceDomainsShare of OpenSRS (Tucows) users
ESPWild West Domains Forwarder884.9%
ESPAmazon SES563.1%
ESPMailgun563.1%
ESPMailchimp211.2%
ESPZendesk191.0%
ESPSendGrid (Twilio)191.0%
ESPMandrill191.0%
ESPMailerLite181.0%
ESPHubSpot90.5%
ESPCampaign Monitor90.5%

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

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Frequently asked questions

How many domains use OpenSRS (Tucows)?

1,811 domains in the Tranco top-1M use OpenSRS (Tucows) as their mailbox provider as of September 10, 2026 (0.27% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is OpenSRS (Tucows) common enough to affect email deliverability testing?

OpenSRS (Tucows) accounts for 0.27% 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 OpenSRS (Tucows) most?

OpenSRS (Tucows)'s largest TLD is .com (65.9% of its domains); it appears across 97 TLDs in total.

Other mailbox providers

Self-Hosted (22.49%)Google Workspace (21.64%)Microsoft 365 (16.95%)Unknown / Other (6.58%)Generic / unmatched (mx*.*) (2.53%)Generic / unmatched (mail.*) (1.94%)Proofpoint (1.88%)Cloudflare Email Routing (1.74%)Yandex 360 (1.61%)Mimecast (1.46%)