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Security report for mailjet.com

Mailjet: Email Delivery Service for Marketing & Developer Teams · Technology · N/a

Low risk. 2 critical or high findings in SSL/TLS.

Security score

82/100

Risk levelLow

0–100, higher is better. How it is calculated

Mailjet is a well-established SaaS company specializing in email delivery services tailored for marketing and developer teams. The platform offers a comprehensive suite of tools including email marketing, transactional email APIs, automation, segmentation, and collaboration features. With over 40,000 companies relying on their services and a professional, multilingual website, Mailjet positions itself as a significant player in the email marketing technology sector. The website demonstrates strong technical maturity, leveraging WordPress CMS with performance optimizations such as lazy loading and modern fonts. SEO and accessibility are well addressed, contributing to a positive user experience. Security posture is solid with HTTPS enforced and no visible vulnerabilities, though explicit security policies and incident response contacts are not publicly available. The absence of WHOIS data reduces transparency but does not detract significantly from the overall legitimacy. Strategic recommendations include publishing detailed security and incident response policies and improving WHOIS transparency to enhance trust.

Scanned

This is an earlier scan of mailjet.com. View the latest report

NIS2 and GDPR posture

GDPR outside view
95/ 100 · Low
Checks completed
7of 7

NIS2 Art. 21(2)

  1. (a) Risk analysis and security policies: Not visible from outside
  2. (b) Incident handling: One indicator
  3. (c) Business continuity, backups and crisis management: Not visible from outside
  4. (d) Supply chain security: Not visible from outside
  5. (e) Secure acquisition, development and maintenance, including vulnerability handling: Partly checked
  6. (f) Assessing the effectiveness of security measures: Not visible from outside
  7. (g) Cyber hygiene and security training: Not visible from outside
  8. (h) Cryptography and encryption: Partly checked
  9. (i) HR security, access control and asset management: One indicator
  10. (j) Multi-factor authentication and secured communications: Not visible from outside

This scan rated NIS2 with an earlier keyword method that is no longer shown; rescan for the per-article view. Risk management, continuity, supply chain, training, MFA, management oversight (Art. 20) and incident reporting (Art. 23) need internal evidence, and Guard cannot tell whether NIS2 applies to this organisation.

GDPR is indicative only, based on publicly visible signals: Articles 7, 12, 13 and 32 of Regulation (EU) 2016/679 and Article 5(3) of the ePrivacy Directive. Not a certification or legal assessment.

Priority findings

2 findings rated critical or high. Fix these first.

  1. SSL/TLS

    TLS encrypts the connection and proves the site is really yours. Weak or expiring certificates trigger browser warnings and put traffic at risk.

    • High

      Weak Protocols Supported

      Server supports weak protocols: TLSv1.1

      What to do: Disable TLS 1.0, TLS 1.1, and all SSL versions

      • CWE-327
      • OWASP A04:2025
      • ASVS V12.1.1
    • High

      Weak SSL Key Length

      SSL certificate uses 256-bit key, which is considered weak

      What to do: Use at least 2048-bit RSA or 256-bit ECC key

      • CWE-326
      • OWASP A04:2025
      • Mozilla TLS: Mozilla Server Side TLS 6.0 intermediate: rsa_key_size 2048

Need hands-on remediation? Email guard@offseq.com

Keep watching mailjet.com

This scan found 15 issues across 6 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

Daily monitoring

Recommended

€25per month

  • TLS certificates and expiry
  • DNS records
  • SPF, DKIM and DMARC
  • Security headers
  • GDPR and NIS2 posture
  • Exposed services
  • Third-party trackers
  • Security score drift

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Results by check

Each check with its score, findings and the evidence it collected.

How this score is calculated

The security score runs 0–100, higher is better. It is the plain average of the security checks that completed in this scan, each counted equally. A check that could not run is left out: it counts neither as a pass nor as a fail.

Counted in this score

SSL/TLS
52
Security headers
85
Email security
72
DNS health
85
Network security
100
GDPR outside view
95
Average
82

Not counted

  • NIS2 outside view: Re-weights evidence from the TLS, email, DNS, network and hygiene checks, so counting it would count that evidence twice. Shown on its own.
  • OffSeq Observations: An AI reading of the site, useful context but not reproducible evidence. Shown on its own.

Findings that cap the score at 49

Each of these is serious on its own, so while any is present the site cannot rate better than high risk, however good the other checks are.

  • The certificate is not trusted by browsers
  • The website is not served over HTTPS
  • A database, remote desktop, file-sharing or Telnet service is reachable from the internet
  • The page loads a script from a compromised source
  • The domain registration has expired
  • SPF authorises every server to send mail as the domain

Partial scans

When the site blocks Guard or most checks cannot run, the score covers only the checks that ran (usually DNS and email), is capped at 75 and is shown as partial, without a risk level.

Risk levels

  • Critical0–25
  • High26–49
  • Medium50–75
  • Low76–100

Technical appendix

Business context, site observations and technical notes gathered during the scan, and the standards behind each reference.

Business context

Business profile

Mailjet operates in the technology sector, focusing on email marketing and delivery solutions. Their business model is SaaS-based, targeting marketing and developer teams with scalable email tools. The company benefits from a strong brand presence, international reach with multiple language versions, and partnerships with related service providers like Mailgun and Email on Acid. Their offerings cover a broad spectrum of email needs from design to deliverability, automation, and validation, indicating diversified revenue streams. The website content and client logos suggest a large enterprise scale with a professional market position. The integration of collaboration tools and AI-powered email generation reflects innovation and responsiveness to market trends. The company is part of Sinch, indicating backing by a larger parent company.

Security posture

Mailjet's website enforces HTTPS and employs modern web security best practices such as script lazy loading and content security measures. However, explicit security policies, vulnerability disclosure programs, and incident response contacts are not publicly documented, which could be improved to enhance transparency and readiness. No exposed sensitive data or vulnerable libraries were detected in the HTML content. The absence of a security.txt file and incident response information suggests room for maturity in security governance. Overall, the security posture is good but could benefit from formalized and published security documentation and contact channels.

Recommendations

  1. Publish a dedicated security policy page outlining security practices and compliance.
  2. Establish and publicize an incident response contact or team for vulnerability reporting.
  3. Implement and maintain a vulnerability disclosure policy and security.txt file.
  4. Increase WHOIS transparency to improve domain trustworthiness and reduce suspicion.
  5. Regularly audit third-party scripts and plugins to mitigate potential vulnerabilities.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Mailjet: Email Delivery Service for Marketing & Developer Teams
Description
Streamline your emailing and boost your sales with Mailjet. We serve all your email and SMS needs with one simple and powerful service.
Key services
Email Marketing, Email API, Email Automation, Segmentation, A/B Testing, Email Validations, Dedicated IP, SMTP Relay, Landing Pages, Real Time Collaboration
Content quality
excellent
Branding
consistent

Technology

Stack
WordPress, Yoast SEO, WP Rocket, Sinch Core Plugin, MJML (email templating), SVG icons, Google Fonts (DM Sans)
Platforms
WordPress
Performance
fast
Mobile
excellent
Accessibility
good
SEO
excellent

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • Lazy loading and script deferring for performance
  • No exposed sensitive data in HTML
  • No inline sensitive credentials

Analytics and tracking

Tracking level
minimal
Privacy practices
good

Advertising

Marketing tools
Yoast SEO, WP Rocket
Transparency
good

Site quality

Design
excellent
User experience
excellent
Content relevance
excellent
Navigation
excellent
Professionalism
excellent
Trustworthiness
high

Key observations

  1. Website is fully accessible with no blocking or WAF challenges.
  2. Content is rich, professional, and targeted at marketing and developer teams.
  3. Strong SEO and technical implementation with modern web technologies.
  4. No explicit contact emails or phone numbers found in main HTML; contact via forms and support URLs.
  5. No security.txt or explicit security policy pages found.
  6. WHOIS data is unavailable, which reduces transparency but does not necessarily indicate malicious intent.
  7. Multiple language versions available indicating international presence.
  8. Use of SVG icons and lazy loading for performance optimization.
  9. No suspicious or malicious external links detected.
Technical notes

Notes

The website is built on WordPress CMS with advanced SEO via Yoast and performance optimization through WP Rocket. It uses modern web fonts (DM Sans), SVG icons, and lazy loading techniques to enhance speed and responsiveness. The site is mobile-optimized with responsive design and accessibility considerations. The technical stack is mature and well-maintained, supporting a fast and user-friendly experience. No hosting provider details were explicitly found, but the infrastructure supports high availability and performance. The use of JSON-LD structured data and Open Graph tags improves search engine visibility and social media integration. Opportunities exist to enhance security documentation and incident response readiness.
Standards and sources

Reference chips under each finding point to the standard, regulation or specification the finding relates to. They are taken from the official datasets below and mapped conservatively: a finding with no defensible link shows none. NIS2 and GDPR references mark where a finding is relevant evidence, not a compliance verdict. Implementing Regulation (EU) 2024/2690 binds digital infrastructure and digital service providers; for other entities it is the most detailed public reading of the Article 21 measures. WCAG, EN 301 549, European Accessibility Act and Web Accessibility Directive references name the requirement an automated accessibility rule relates to; they are not a conformance verdict.

Retrieved 2026-10-25

Earlier scans of this domain

  1. 82/100Low21 findingsView report
  2. 75/100Medium18 findings · partial scanView report
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