📬 Companies without MTA-STS
These domains have no MTA-STS configured, leaving email in transit vulnerable to TLS downgrade attacks between mail servers.
39
Companies affected
2378
Total scanned
2%
Prevalence
Domain
Score
Tier
MTA-STS Status
+34 more companies
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Which companies don't have MTA-STS configured?
MTA-STS (Mail Transfer Agent Strict Transport Security) prevents TLS downgrade attacks on email in transit between mail servers. Without it, an attacker can intercept the SMTP connection and strip TLS encryption, reading emails in plaintext. Despite being a critical email security layer, MTA-STS adoption remains very low.
LynxRadar scanned 2378 domains including Fortune 500 companies and Y Combinator startups. Of those, 39 (2%) were found to have this security gap. The data above is updated continuously as new domains are scanned. Scan any domain to check its status.