“If I see ‘0’ in the ‘Spam’ column of my campaign report, does that mean there were truly zero spam issues? I ask because another campaign shows 6, and I want to understand if this information is accurate and how it can be verified.”

This number represents the count of user-generated spam complaints.

Most email services (like Gmail, Outlook, etc.) have a “Mark as spam” button. When a recipient clicks this button on an email sent from our platform, the email service informs us through a feedback loop. We then record that action in your report. This number is therefore a direct count of these actions.
It’s important to note that some recipients use the “Mark as spam” button as a way to unsubscribe from future mailings instead of using the proper unsubscribe link. Email service providers are aware of this behavior and take it into account in their statistical analysis.
However, this number does not show how many emails were automatically filtered into the spam folder by an email service’s algorithm without any user action. An email can be delivered directly to the spam folder without being “marked as spam” by the user, and that event is not captured by this specific metric.