DKIM Record Checker

What this tool checks:

• DKIM Record Validation - Verifies DKIM record syntax and structure
• Public Key Analysis - Examines the RSA public key and estimates key length
• Parameter Explanation - Breaks down each DKIM tag (v, k, h, p, s, t, etc.) with detailed explanations
• Security Assessment - Identifies potential security issues like weak keys, testing mode, or deprecated algorithms
• Multiple Selectors - Supports checking multiple DKIM selectors for domains with multiple signing keys

Why DKIM matters:

DKIM provides cryptographic proof that an email hasn't been altered and comes from an authorized server. It's a critical component of email authentication that works alongside SPF and DMARC to prevent email spoofing and improve deliverability.

Common DKIM issues:

• Weak key length (less than 2048 bits)
• Testing mode enabled in production (t=y flag)
• Using deprecated SHA-1 hash algorithm
• Revoked keys (empty p= value)