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Business Systems House 2026
Outbound SMTP Relay Hardening & DKIM Cryptographic Signing
Postfix Exim MTA DKIM DMARC SPF OpenSSL Exchange Online
Outbound SMTP Relay Hardening & DKIM Cryptographic Signing
Hardened enterprise transactional mail relays to guarantee high deliverability rates and protect corporate email domains against spoofing.
Key Features & Implementation
- 2048-bit DKIM Key Generation: Generated and rotated RSA 2048-bit cryptographic key pairs for domain-level outbound mail signing.
- DMARC Enforcement Baseline: Enforced DMARC policies transitioning from p=none to p=reject with automated failure reporting endpoints.
- Relay Access Control: Restricted outbound SMTP relaying strictly to authenticated internal application IPs and authorized service accounts.