Enterprise Email Infrastructure Whitepaper * margin: 0; padding: 0; box-sizing: border-box; body font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: linear-gradient(145deg, #f1f5f9 0%, #e6edf5 100%); padding: 20px; line-height: 1.5; color: #1