Testing Process & Interpretation

How often should I run inbox placement tests? How do I interpret the results (e.g., % inbox, % spam, % missing)? How should results be interpreted (directional, not absolute)? What actions should I take based on poor inbox placement results? How do I test placement in different tabs (e.g., Gmail Promotions)? How do you test placement before major campaigns? What’s the best time to test (before or after warming)? How do you test per-ISP deliverability? How to test content vs engagement impact separately? How do you test with and without tracking pixels? How to test different “From” names or reply-to addresses? What’s the difference between A/B testing content vs domain reputation? How to isolate one variable for deliverability testing? How to interpret mixed results (inbox + spam + missing)? What are common misinterpretations of inbox test results? How do you detect false negatives or false positives in tests? How can you combine testing with Postmaster diagnostics?