Can low open rates cause spam filtering directly?

Low open rates contribute to filtering but the relationship is nuanced:

Providers track engagement patterns including whether recipients open, click, or ignore messages. Consistently ignored mail signals that recipients do not want it.

The mechanism is correlational. Low opens do not directly trigger spam filtering. Rather, sustained patterns of recipients ignoring your mail teach providers that your content is unwanted.

Apple Mail Privacy Protection complicates open tracking by auto-loading images, making open rates less reliable as a metric.

Other signals like complaints, spamtrap hits, and authentication carry more direct weight than open rates alone.

Low opens are a symptom more than a cause. The underlying disease is sending to people who do not want your mail, which manifests in many metrics, opens being just one.