Do bounce rates directly cause blocking?

Not Directly. High bounce rates indicate list quality problems that concern providers, but bounces themselves do not directly cause blocking. Sustained high bounces damage reputation over time.

Very high bounce rates (like sending to a purchased list) can trigger immediate filtering. Normal bounce fluctuations require ongoing attention but do not cause instant blocking.

Maintain good bounce handling: suppress hard bounces immediately, manage soft bounces appropriately, and investigate spike causes. Clean lists prevent bounce related reputation problems.