Email Sending Reputation Monitoring

Definition

Email sending reputation monitoring is the continuous observation of how mailbox providers evaluate your sending identity. Monitoring covers IP address reputation, domain reputation, sender score from third-party services, feedback loop data from major ISPs, complaint rate trends, blacklist status, and authentication pass rates. Effective monitoring detects reputation changes before they cause significant inbox placement problems, enabling proactive intervention.

Monitoring Components

• Sender score: Composite third-party rating across major ISPs
• IP reputation: Per-IP historical sending and engagement data
• Domain reputation: Domain-level evaluation separate from IP reputation
• Feedback loop data: Spam complaint reports from participating ISPs
• Blacklist status: Presence on known email blacklists
• Authentication pass rates: SPF, DKIM, and DMARC alignment percentages
• Bounce classification: Hard versus soft bounce ratios as deliverability indicators

Best Practices

• Monitor reputation metrics daily with automated alerts for significant changes
• Establish baselines per ISP since reputation dynamics differ across providers
• Investigate reputation changes within 24 hours of detection to minimise impact
• Correlate reputation changes with sending activity changes (volume spikes, new segments, content changes)
• Maintain a reputation incident log that documents changes, investigations, and resolutions for pattern identification