How do I manage reputation across multiple domains?

Managing multiple domains requires systematic monitoring and balanced distribution.

Monitoring setup:

Enroll each domain in Gmail Postmaster Tools

Set up Microsoft SNDS access for each sending IP

Monitor blocklists for each domain

Track deliverability metrics per domain

Volume distribution:

Spread sending evenly across domains when possible

Don't concentrate volume on best-performing domain (burns it out)

Rotate domains to give each rest periods

Adjust distribution based on reputation indicators

Problem isolation:

When one domain shows issues, reduce its volume

Investigate root cause before shifting volume to other domains

Don't let problem patterns spread across domains

Operational practices:

Maintain consistent authentication across all domains

Use separate mailboxes per domain for proper isolation

Document which campaigns use which domains

Plan for domain rotation and retirement

Each domain is a separate reputation asset. A fleet requires individual maintenance for each vessel, not just the flagship.