How to test for “silent junking”?

Detecting silent spam filtering:

Seed testing:

Maintain test accounts at major providers

Send test emails

Check inbox and spam folders

Document placement

Real recipient verification:

Ask trusted recipients to check spam

Internal team members at various providers

Metric analysis:

Compare open rates by provider

Dramatic drop at one provider indicates silent filtering

Zero engagement suggests spam placement

Panel data:

Third-party services tracking real inbox placement

Provides visibility beyond your seeds

Test shipments reveal where cargo actually ends up.