What engagement signals matter most for cold sending?

Different engagement signals carry different weight for cold sender reputation.

Strongest positive signals:

Replies: Direct evidence of wanted communication

Moved from spam: Recipient explicitly overrides filter decision

Added to contacts: Signals expected future communication

Moderate positive signals:

Opens: Indicates visibility but increasingly unreliable due to privacy protections

Clicks: Shows engagement with content

Forwards: Sharing suggests value

Strong negative signals:

Spam complaints: Devastating to reputation, even small percentages

Deleted without opening: Pattern of irrelevance

Blocked sender: Recipient explicitly rejected you

Accumulating neutral signals:

Ignored messages: No engagement compounds into negative signal over time

Messages sitting unread in inbox don't help

For cold email specifically:

Focus on generating replies over other metrics

Minimize complaint risk through targeting and easy opt-out

Open rates are informational but unreliable

Quality of response matters more than volume of sending