By grouping IPs into virtual-mta pools, you can rotate your sending identity. If one IP gets "cold" (low reputation), you can shift traffic to another pool without rewriting your entire application logic. 4. Advanced Bounce Handling
; Sample template for virtual-mta assignment by header/transaction routing-rule high-priority
# Virtual MTA for a specific IP smtp-source-ip 1.2.3.4 host-name ://yourdomain.com domain-key selector1, yourdomain.com, /etc/pmta/dkim.private.key # Virtual MTA Pool for load balancing multiple IPs virtual-mta vmta1 virtual-mta vmta2 Use code with caution. Copied to clipboard 4. Domain Directives (Rate Limiting)
