duolingo.com email security: SPF, DKIM & DMARC
Is duolingo.com spoofable? See duolingo.com's SPF, DKIM, DMARC and MTA-STS records and find out if this domain is protected against email spoofing.
Last updated: June 3, 2026
SPF
OKv=spf1 ip4:100.25.59.11 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.8.0/21 ip4:52.73.203.75 ip4:52.70.130.33 include:amazonses.com include:_spf.google.com include:_spf.salesforce.com include:mail.zendesk.com include:aspmx.pardot.com ~allDKIM
OKSelectors: google, k1, s1, s2, zendesk1, zendesk2DMARC
OKv=DMARC1; p=reject; sp=reject; fo=1; rua=mailto:re+lhqmqj57zra@DMARC.postmarkapp.com,mailto:re+xu5r3a1wrlo@inbound.dmarcdigests.com,mailto:dmarcreports@duolingo.com; ruf=mailto:dmarcreports@duolingo.com; adkim=r; aspf=rMX
OKaspmx.l.google.com, alt1.aspmx.l.google.com, alt2.aspmx.l.google.com, aspmx3.googlemail.com, aspmx5.googlemail.com, aspmx4.googlemail.com, aspmx2.googlemail.comRecommendations
1Add MTA-STS to enforce TLS encryption for incoming emails
Without MTA-STS, an attacker performing a man-in-the-middle attack can downgrade the connection between mail servers to plaintext, intercepting emails in transit. MTA-STS tells sending servers to only deliver via TLS with a valid certificate, preventing downgrade attacks.
Run a live analysis
The results above are updated daily. For an instant check of duolingo.com, run a live analysis.
Analyze duolingo.com liveFrequently asked questions about duolingo.com
Is duolingo.com spoofable?
No. duolingo.com is protected against email spoofing with a robust configuration. Email security score: 90/100 (grade A).
Does duolingo.com have an SPF record?
Yes, duolingo.com publishes an SPF record (~all qualifier).
What is duolingo.com's DMARC record?
duolingo.com publishes a DMARC record (_dmarc.duolingo.com) with a p=reject policy.
Does duolingo.com use DKIM?
Yes, DKIM signatures were detected for duolingo.com.
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Guides to understand these results
SPF Guide
Understand how SPF defines which servers are authorized to send emails for a domain.
DKIM Guide
Discover how DKIM cryptographically signs your emails to guarantee their authenticity.
DMARC Guide
Learn how DMARC orchestrates SPF and DKIM to protect your domain.
MTA-STS Guide
Learn how MTA-STS enforces TLS encryption to protect your emails in transit.
SPF vs DKIM vs DMARC
Compare the three protocols and understand how they work together.