How can domain diversification act as a reputation firewall?

Domain diversification as firewall:

Separation strategy:

Transactional on main domain

Marketing on subdomain

Cold outreach on separate domain

Risky activities fully isolated

Firewall benefits:

Marketing problems do not affect transactional

Experiments do not risk main reputation

Can sacrifice isolated domains if needed

Implementation:

Proper authentication per domain

Clear routing rules

Separate IP pools if possible

Documentation of domain purposes

Isolation protects your most valuable sending assets.

Damage control: compartmentalization prevents one problem from sinking everything.