I built a modular magazine email system on a placeholder masthead. One Mailchimp master template holds 10 modules (masthead, cover, contents, two feature layouts, pull quote, the list, launch cover, waitlist status and a call to action), each one a repeatable block the editor offers as a menu. A biweekly issue, a launch and a waitlist email are built from that library, and together with the template they pass 38 inbox checks, the largest email at 12,445 bytes, well under Gmail's clipping size, with every text pair clearing AA contrast in light and dark mode (lowest 6.21). The four editorial images, a portrait, a still life, a textile study and a stage reveal, are drawn in code in one warm palette and exported at twice their slot width for high-density phones. The issue cover exports at 1080×1350 and 1080×1080 and the launch cover at 1080×1920 for social.