What are the fastest signals of domain-level distrust?

Fast domain distrust indicators:

Gmail Postmaster: Domain reputation shows "Low" or "Bad" while IP reputation may be different.

Bounce messages: Blocks citing your domain specifically rather than IP.

DMARC failures: Reports showing domain alignment issues.

Cross-IP pattern: Same domain on different IPs shows same problem.

Content filtering: Blocks triggered by domain in links or From address.

New sending sources fail: Fresh IPs immediately have problems when using the domain.

Domain reputation travels with the brand. Cannot escape by changing IPs alone.

When the company name is blacklisted, using different ships does not help.