Soft Bounce

A soft bounce is a temporary email delivery failure caused by short-term issues such as a full mailbox, server timeout, message size limits, or transient receiving errors. Unlike hard bounces, soft bounces do not always require immediate list removal, but repeated soft bounces can still hurt sender reputation if ignored. Effective handling includes retry logic, threshold-based suppression, and tracking by ISP to identify systemic routing problems. Teams should monitor bounce categories at campaign and segment level because spikes often signal technical issues or deteriorating list quality. Combining soft-bounce monitoring with authentication checks and engagement-based segmentation helps preserve inbox placement. Operational discipline here improves campaign reliability and protects long-term deliverability performance.