How do they detect spam filter triggers?

Spam testing sends your email through representative spam filters, reporting scores and specific triggers. Tools maintain filter environments simulating SpamAssassin, **Gmail**, **Outlook**, and other filtering systems.

Detection output: overall spam scores, specific rules triggered (all caps, suspicious links, spammy phrases), authentication status, and comparison against typical thresholds. Reports highlight what to fix.

Limitations: test environments approximate production filters but can't replicate recipient-specific factors (engagement history, personal preferences). Test results indicate likely treatment, not guaranteed outcomes. Use spam testing to catch obvious issues; actual delivery depends on broader factors.