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quizlet.com

Checked 2026-10-22 10:24 UTC · first added 2026-10-21
✗Problems found Score 72 of 100

Domain & DNS

fail

23 passed 3 warn 1 failed

Areas

iRegistration !Delegation ✗Nameservers ✓SOA ✓DNSSEC iRecords

Problems

  • ✗
    Nameservers not responding
    Nameservers · These addresses did not answer, so resolvers waste time on timeouts: cns1.quizlet.com (104.16.133.27): read udp 46.225.38.91:44457->104.16.133.27:53: i/o timeout; cns1.quizlet.com (104.16.134.27): read udp 46.225.38.91:34303->104.16.134.27:53: i/o timeout; cns2.quizlet.com (104.16.133.27): read udp 46.225.38.91:47825->104.16.133.27:53: i/o timeout; cns2.quizlet.com (104.16.134.27): read udp 46.225.38.91:54708->104.16.134.27:53: i/o timeout.
    #14
  • !
    NS sets differ
    Delegation · The nameservers at the parent and in the zone should be the same. Only at the parent: cns1.quizlet.com, cns2.quizlet.com; only in the zone: ian.ns.cloudflare.com, lily.ns.cloudflare.com. ian.ns.cloudflare.com, lily.ns.cloudflare.com report NS ian.ns.cloudflare.com lily.ns.cloudflare.com.
    #7
  • !
    Glue differs from the zone
    Delegation · The addresses at the parent (glue) differ from the addresses in the zone: cns1.quizlet.com (glue 173.245.58.37, zone 104.16.133.27, 104.16.134.27); cns2.quizlet.com (glue 173.245.59.32, zone 104.16.133.27, 104.16.134.27). Update the glue at your registrar.
    #8
  • !
    Software version disclosed
    Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ian.ns.cloudflare.com: "2026.10.2"; lily.ns.cloudflare.com: "2026.10.2". Hide or replace the version string.
    #17

Recent checks

✗

Full report

Domain & DNS report for quizlet.com ›

Mail

warn

29 passed 3 warn 0 failed

Areas

✓SPF ✓DMARC !DKIM ✓DNSSEC !MX !TLS ✓BIMI

Problems

  • !
    More than 5 MX records
    MX · Found 7 MX records, which is more than the recommended maximum of 5. Too many MX records may indicate a misconfiguration.
    #13
  • !
    1024-bit DKIM key
    DKIM · 1024-bit RSA keys are the minimum and are considered weak today: google (1024 bits), s2 (1024 bits). Rotate to a 2048-bit key.
    #23
  • !
    Not configured
    TLS · MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.
    #32

Recent checks

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