SMTP Vulnerabilities Scanner
Tests SMTP servers for open relay and security issues.
What is SMTP Vulnerabilities?
SMTP Vulnerability testing identifies security issues in mail servers: open relay (allowing spam forwarding), missing authentication, weak encryption, user enumeration (VRFY/EXPN), command injection, and email spoofing enablers (missing SPF/DKIM/DMARC). These issues enable spam, phishing, and data theft.
Why is This Important?
A vulnerable mail server can be abused to send spam (getting your IP blacklisted), enable phishing attacks using your domain, expose valid email addresses through enumeration, or leak sensitive emails through interception. Email remains a primary attack vector and must be secured.
How It Works
1. Network Discovery
Scans and fingerprints network services, identifying open ports, protocols, and service versions.
2. Protocol Analysis
Tests protocol implementations for misconfigurations, weak encryption, and known vulnerabilities.
3. Infrastructure Assessment
Provides comprehensive network security posture with prioritized remediation recommendations.
Key Capabilities
Enterprise network security assessment covering infrastructure, protocols, and service configurations.
- Comprehensive port and service discovery
- Protocol-specific vulnerability checks
- TLS/SSL configuration analysis
- Legacy protocol detection and assessment
- Network segmentation validation
Frequently Asked Questions
What is an open relay and why is it dangerous?
An open relay accepts email from any sender to any recipient without authentication. Spammers abuse these to send millions of spam emails. Your server gets blacklisted, legitimate emails are blocked, and you may face legal liability. Test by sending email to external domains without auth.
What are VRFY and EXPN vulnerabilities?
VRFY confirms if a username exists; EXPN expands mailing lists to members. Both enable user enumeration. Attackers build valid email lists for targeted phishing or brute force. Most servers should disable these commands or restrict them to authenticated users.
How do SPF, DKIM, and DMARC protect email?
SPF specifies which IPs can send for your domain. DKIM cryptographically signs emails. DMARC tells receivers what to do with failures and provides reporting. Together, they prevent domain spoofing. Missing any of these enables attackers to send emails 'from' your domain.
What SMTP encryption issues should I look for?
Check for: STARTTLS support (encrypts connections), certificate validity, support for modern TLS versions, SMTP downgrade attacks (stripping STARTTLS), and MTA-STS configuration (preventing STARTTLS stripping). Unencrypted SMTP exposes email content to interception.
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