What does “domain reputation block” mean?

A domain reputation block rejects mail based on your domain's history:

What it means:

Your domain (From address domain) has poor reputation. Changing IPs will not help. The domain itself is flagged.

How domain reputation is damaged:

Consistent spam complaints. Poor engagement metrics. Spamtrap hits. Domain used in phishing. DMARC failures from spoofing.

Why domain reputation matters more now:

ISPs increasingly focus on domain signals. Harder to change domains than IPs. Follows you across ESP migrations.

Detection:

Google Postmaster Tools domain reputation. Bounce messages referencing domain. Provider-specific dashboards.

Resolution:

Long-term reputation repair. Reduce volume, improve quality. Re-engagement campaigns. Address authentication issues.

Domain reputation is your flag and registry. It identifies you regardless of which ship you sail.