MTA Routes mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), MTA Routes is the mailbox provider for 186 domains — 0.03% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

MTA Routes is a mail hosting and transfer service that processes message routing for smaller domains and niche operators across a distributed, globally-dispersed footprint. Unlike bulk consumer-facing providers, it serves a long-tail market of smaller sites, regional operators, and self-managed mail infrastructure, with particular density in English-language and dot-com registrations.

For senders and mail administrators, MTA Routes' presence signals a secondary but material deliverability surface in smaller-domain segments. Its pairing with Symantec MTA infrastructure and scattered international deployment means testing and troubleshooting bounce rates, authentication failures, or filtering issues in smaller-operator audience lists should account for MTA Routes as a distinct hosting layer with its own authentication and filtering posture.

Where MTA Routes sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00000.0%
Top 10,00000.0%
Top 100,000105.4%
Top 1,000,00015080.6%
Unranked2614.0%

Top-level domain split

TLDDomainsShare
.com7138.2%
.nl2412.9%
.org2010.8%
.co.uk189.7%
.net147.5%
.com.au63.2%
.de31.6%
.co.za31.6%
.org.uk21.1%
.au21.1%

What MTA Routes users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 186 domains.

TypeServiceDomainsShare of MTA Routes users
ESPSymantec MTA Routes10657.0%
ESPMailchimp2010.8%
ESPAmazon SES179.1%
ESPMailgun179.1%
ESPMandrill179.1%
ESPSendGrid (Twilio)158.1%
ESPExclaimer84.3%
ESPSalesforce84.3%
ESPHubSpot84.3%
ESPZendesk52.7%

SPF and authentication alignment at the hosting layer

Because MTA Routes operates as a mail hosting service rather than a major consumer-facing platform, authentication chains require explicit alignment with its infrastructure. Domains hosted on MTA Routes must authorise its mail server IP ranges in their SPF record; DKIM signing integrity may be affected by how the platform processes outbound messages. Senders experiencing authentication rejections or filtering issues with MTA Routes–hosted domains should verify SPF authorisation and DKIM configuration, as these are common failure points when domain owners' authentication policies are not aligned with their mail provider's infrastructure.

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

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Frequently asked questions

Should I test email deliverability against MTA Routes?

Unless your audience explicitly includes smaller domains or niche operators known to use MTA Routes, it is not a primary testing target like Gmail or Outlook. However, if bounce rates or filtering issues cluster among smaller or regional sites, investigating MTA Routes' filtering policies and verifying your SPF and DKIM authorisation for those domains can often resolve delivery problems.

How many domains use MTA Routes?

186 domains in the Tranco top-1M use MTA Routes as their mailbox provider as of July 13, 2026 (0.03% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is MTA Routes common enough to affect email deliverability testing?

MTA Routes accounts for 0.03% 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 MTA Routes most?

MTA Routes's largest TLD is .com (38.2% of its domains); it appears across 29 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%)