Reputation is the dominant factor in inbox placement. Content matters far less than the trust a provider has in your domain.
The metrics that matter#
- Authentication pass rate: share of mail passing SPF, DKIM, and DMARC alignment. Healthy: 99% or higher.
- Spam complaint rate: Gmail enforces at 0.3%; stay under 0.1%.
- Hard bounce rate: under 2%; above 5% triggers platform reviews.
- Inbox placement: above 90% across major providers via seed tests.
- Engagement: click and reply rates by segment; opens are unreliable after Mail Privacy Protection.
Where to read them#
- Google Postmaster Tools for Gmail domain reputation, spam rate, and authentication.
- Microsoft SNDS and JMRP for Outlook.com IP reputation and complaints.
- Your ESP's delivery and bounce reports.
- DMARC aggregate reports for authentication by source.
Improving the numbers#
- Register in Google Postmaster Tools and Microsoft SNDS to see your domain and IP reputation directly.
- Keep spam complaints below 0.1% (Gmail's threshold is 0.3% for enforcement) and hard bounces below 2%.
- Segment by engagement and stop sending to contacts inactive for 90+ days.
- Authenticate with SPF, DKIM, and DMARC so reputation accrues to your domain rather than a shared IP.
- Ramp volume gradually after any pause longer than two weeks.
Frequently asked questions#
Domain reputation vs IP reputation: which matters more?
Domain reputation now dominates at Gmail and Yahoo. IP still matters for Microsoft and for dedicated-IP senders.
How long does it take to repair a bad reputation?
Four to eight weeks of clean, low-volume sending to engaged recipients is typical.