Do spam filters read every email?

Spam filters do not "read" emails the way humans do. They analyze signals algorithmically without human comprehension of meaning.

Filters examine patterns and characteristics: word frequencies, structural elements, header information, and authentication data. They match these against models trained on spam and legitimate mail.

Machine learning models process features without understanding content. The model knows that certain patterns correlate with spam without comprehending what the words mean.

For efficiency, filters often make early decisions before fully analyzing content. A message from a blocklisted IP may be rejected before content is ever scanned.

Human review happens only in special cases: abuse investigations, false positive analysis, or policy development.

Filters analyze, pattern-match, and calculate rather than read. They see signals where we see sentences.