How can inconsistent templates shift you between tabs?

Template inconsistency confuses classification:

If you alternate between heavily formatted promotional templates and plain text personal-style messages, Gmail receives mixed signals about your content type.

Classification may vary unpredictably as the algorithm tries to match each send to patterns.

Consistency helps: Maintain relatively consistent formatting so Gmail can reliably categorize your sends.

This does not mean every message must be identical, but dramatic swings between commercial and personal styling can create placement instability.

Ships flying different flags on different voyages confuse the port officials.