Act as a senior email marketing strategist with 10+ years of experience in AI-driven campaign optimization. Design a step-by-step workflow for automating email A/B testing using [AI_TOOL_NAME] to test [VARIABLE_1] (e.g., subject lines) against [VARIABLE_2] (e.g., call-to-action buttons) for [TARGET_AUDIENCE]. Include: 1. How to set up the AI model to analyze historical performance data 2. Criteria for automatic winner selection (open rates, click-through rates, etc.) 3. Integration with [EMAIL_PLATFORM] for seamless deployment 4. How the system should handle inconclusive results 5. Recommended reporting frequency for human review Provide 3 key metrics the AI should prioritize when optimizing future tests based on [BUSINESS_GOALS].