How do ESPs enforce bounce thresholds?

ESPs enforce bounce thresholds to protect their infrastructure:

Enforcement mechanisms:

Automated warnings: Email alerts when rates spike. Account flags: Internal monitoring increased. Sending restrictions: Volume or rate limits applied. Manual review: Human evaluation required. Suspension: Sending blocked entirely.

Typical enforcement tiers:

2% hard bounces: Warning notification. 5% hard bounces: Account flagged for review. 10% hard bounces: Sending suspended pending explanation.

Remediation requirements:

Explain bounce spike. Provide list hygiene plan. May require list cleaning. Demonstrate improved practices.

Why ESPs care:

Shared IP reputation affects all customers. Poor senders damage ESP relationships with ISPs. Compliance requirements for ESP industry.

ESPs are gatekeepers protecting their harbor. Abusers threaten everyone's access.