Why use multiple domains for cold outreach?

Using multiple domains for cold outreach is a risk management strategy that isolates reputation damage.

Risk distribution:

If one domain gets blocklisted, campaigns on other domains continue

Reputation damage is contained to the affected domain

Critical email (transactional, opted-in marketing) stays protected

Volume management:

Each domain has effective sending limits

Multiple domains enable higher total volume while respecting per-domain limits

Distributes sending load across infrastructure

Testing flexibility:

Test different approaches on different domains

Isolate experiments from primary sending

Compare performance across domain configurations

Considerations:

Each domain requires setup, warmup, and monitoring

Management complexity increases with domain count

Mailbox providers can connect patterns across related domains

This is not a license for abusive practices

Multiple domains provide operational resilience but don't exempt senders from responsible practices. Multiple vessels protect the fleet from total loss, but they still must sail responsibly.