Mailjet (Sinch) email service provider (ESP)

According to Live Direct Marketing's daily Tranco top-1M scan (July 12, 2026), Mailjet (Sinch) is the email service provider (ESP) for 13,126 domains — 2.13% of 617,244 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.

Key facts

Mailjet is an email service platform owned by Sinch, a global communications company. Mailjet provides transactional and marketing email services to organisations ranging from startups to mid-market enterprises, and is typically embedded as an outbound mail provider for customers who need reliable delivery without running their own mail infrastructure.

Mailjet's footprint across the web is concentrated in smaller and mid-sized organisations rather than the largest brands; it appears across many country-code and generic top-level domains, and is frequently deployed alongside Microsoft 365 environments. Understanding Mailjet's role in your inbound or outbound mail chain is important for diagnosing delivery issues, validating SPF/DKIM configurations, and assessing reputation factors that may affect mail routing.

Where Mailjet (Sinch) sits in the Tranco ranking

Tranco rank bandDomainsShare of its base
Top 1,00040.0%
Top 10,0001311.0%
Top 100,0001,45511.1%
Top 1,000,00010,24278.0%
Unranked1,2949.9%

Top-level domain split

TLDDomainsShare
.com5,37440.9%
.fr1,47111.2%
.de1,1458.7%
.org6154.7%
.net3822.9%
.nl2922.2%
.co.uk1991.5%
.fi1871.4%
.io1841.4%
.be1761.3%

What Mailjet (Sinch) users also use

Cross-tabulated from the same daily snapshot — the other email services seen on the same 13,126 domains.

TypeServiceDomainsShare of Mailjet (Sinch) users
MailboxMicrosoft 3654,06631.0%
MailboxGoogle Workspace3,45226.3%
MailboxSelf-Hosted1,2269.3%
MailboxUnknown / Other9717.4%
MailboxOVH Mail5043.8%
MailboxGeneric / unmatched (mx*.*)2792.1%
ESPAmazon SES1,2639.6%
ESPZendesk1,1318.6%
ESPSendGrid (Twilio)9677.4%
ESPMandrill9487.2%

SPF include mechanism and multi-tenant sender reputation

Mailjet operates shared infrastructure for transactional and marketing email, which means its SPF include mechanisms (such as include:mailjet.com or related DNS entries) appear on sending domains across the internet. This shared footprint creates interdependencies in sender reputation: if one customer on the platform engages in poor practices or triggers complaints, it can affect the broader reputation of the Mailjet netblock, which in turn influences filtering decisions for all senders using its infrastructure. Recipients and mail administrators monitoring Mailjet traffic should treat reputation signals for Mailjet's IP ranges as a proxy for the collective behaviour of its customer base, rather than as a single organisation's reputation.

See the full Mailjet (Sinch) data page (KPI cards, trend, sample domains) →

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Frequently asked questions

Should I test email deliverability against Mailjet?

Testing against Mailjet is worthwhile if your own organisation or your recipients' organisations use it for outbound mail, or if you interact with Mailjet-hosted sending domains; however, Mailjet's shared infrastructure means that blocklist listings or sender reputation issues on the platform will affect all customers using it, so monitoring Mailjet's reputation in your receiving environment is more important than testing against it specifically.

How many domains use Mailjet (Sinch)?

13,126 domains in the Tranco top-1M use Mailjet (Sinch) as their email service provider (ESP) as of July 12, 2026 (2.13% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.

Is Mailjet (Sinch) common enough to affect email deliverability testing?

Mailjet (Sinch) accounts for 2.13% of SPF-publishing domains 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.

Is Mailjet (Sinch) growing or declining?

Mailjet (Sinch) is growing — its share moved +0.02 pp over the last 30 days (as of July 12, 2026).

Which countries or TLDs use Mailjet (Sinch) most?

Mailjet (Sinch)'s largest TLD is .com (40.9% of its domains); it appears across 301 TLDs in total.

Other email service provider (ESP)s

Amazon SES (6.21%)SendGrid (Twilio) (4.75%)Mailgun (4.11%)Zendesk (3.87%)Mailchimp (3.69%)Mandrill (3.36%)HubSpot (3.18%)Salesforce (2.62%)Cloudflare Email Routing (1.80%)Brevo (ex-Sendinblue) (1.43%)