Symantec MessageLabs mailbox provider

According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Symantec MessageLabs is the mailbox provider for 555 domains — 0.08% of 658,711 domains with MX records. Detection method: primary MX record (lowest preference).

Key facts

Symantec MessageLabs is a managed email hosting and filtering platform provided by Broadcom as part of its email security suite. It offers cloud-based mail hosting, filtering, archival, and compliance capabilities for organisations that do not operate their own mail infrastructure.

In the Tranco top-1M web infrastructure, Symantec MessageLabs serves primarily smaller and medium-sized organisations scattered across many geographies and domain extensions, rather than the largest enterprises. Its frequent co-occurrence with Amazon SES suggests it is particularly popular amongst hosting providers and organisations integrating it into broader cloud infrastructure; this pattern means email professionals sending to MessageLabs-hosted domains should ensure DMARC, SPF, and DKIM compliance, and may encounter filtering rules calibrated for the long tail rather than enterprise-scale senders.

Where Symantec MessageLabs sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00020.4%
Top 10,000132.3%
Top 100,00011320.4%
Top 1,000,00040372.6%
Unranked244.3%

Top-level domain split

TLDDomainsShare
.com23342.0%
.co.jp417.4%
.co.uk417.4%
.net285.0%
.org254.5%
.gov.uk122.2%
.de112.0%
.br91.6%
.jp91.6%
.org.uk81.4%

What Symantec MessageLabs users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 555 domains.

TypeServiceDomainsShare of Symantec MessageLabs users
ESPAmazon SES458.1%
ESPSalesforce417.4%
ESPSendGrid (Twilio)356.3%
ESPMailchimp285.0%
ESPMandrill254.5%
ESPZendesk152.7%
ESPMailgun142.5%
ESPHubSpot142.5%
ESPHDEMS122.2%
ESPCampaign Monitor112.0%

Filtering and authentication requirements for MessageLabs recipients

Organisations using Symantec MessageLabs as their mail host expect their receiving infrastructure to enforce DMARC, SPF, and DKIM validation; any sender targeting MessageLabs-hosted domains must maintain proper authentication records and avoid IP reputation issues, as the platform's filtering logic is tuned to protect smaller organisations that typically cannot field dedicated security teams. Because MessageLabs is often deployed via hosting providers, filtering policies may be conservative and less forgiving of marginal authentication signals than enterprise platforms accustomed to high sender traffic volumes.

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

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Frequently asked questions

Should I test my email deliverability against Symantec MessageLabs?

If your recipients include organisations using MessageLabs as their mail host (common for smaller businesses and those using certain hosting providers), you should validate that your authentication and sending reputation meet its requirements; however, MessageLabs is not a primary bottleneck for most senders, so testing against it is less critical than validating against major consumer mailbox providers and ISP filters.

How many domains use Symantec MessageLabs?

555 domains in the Tranco top-1M use Symantec MessageLabs as their mailbox provider as of July 13, 2026 (0.08% of domains with MX records), according to Live Direct Marketing's daily DNS scan.

Is Symantec MessageLabs common enough to affect email deliverability testing?

Symantec MessageLabs accounts for 0.08% 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 Symantec MessageLabs most?

Symantec MessageLabs's largest TLD is .com (42.0% of its domains); it appears across 75 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%)