How do ESPs prevent account compromise or abuse?

Account compromise is a serious threat: attackers who gain access to legitimate accounts use them to send spam or phishing from trusted infrastructure. ESPs deploy multiple defensive layers.

Authentication security:

Two-factor authentication (2FA) requirements

Strong password policies

Session management and timeout controls

IP-based access restrictions

API key security:

Scoped API keys (limited permissions)

Key rotation capabilities

Monitoring of API key usage patterns

Alerts on unusual API activity

Sending anomaly detection:

Baseline normal sending patterns per account

Alert or pause when patterns deviate dramatically

Sudden volume spikes trigger review

Geographic or timing anomalies flagged

Rate limiting:

Per-account sending limits

Gradual limit increases based on history

Hard caps even for established accounts

Content monitoring:

Real-time content scanning

Pattern matching for known spam/phishing templates

URL checking against threat databases

Response capabilities:

Automatic pausing of suspicious accounts

Rapid response teams for compromise incidents

Customer notification of detected issues

Compromised accounts damage both the individual sender and shared infrastructure, so ESPs invest heavily in prevention.