Email Subject Line Tester

This is a lightweight, rule-based heuristic checker, not a real inbox-placement test. It starts every subject at 100 and subtracts points for four patterns. Length outside 20-60 characters costs 20 points, because very short lines underperform and longer ones get truncated in mobile previews (most clients show roughly 30-50 characters before cutting off). A subject written entirely in capitals (and longer than five characters) costs 30 points, since shouting in all caps is a long-standing spam signal. Two or more consecutive ! or ? characters cost 15 points. Finally, each match against a built-in list of ten classic trigger words and phrases (free, guarantee, act now, click here, cash, winner, prize, viagra, casino, make money) costs 10 points. The matching is a plain case-insensitive substring check, so guarantee inside guaranteed still counts, and there is no detection of personalization, emojis, sender reputation, or modern Bayesian filtering. Treat the number as a quick sanity nudge toward shorter, calmer copy, then validate real deliverability with a seed-list test or a tool like Mail-Tester or GlockApps.