Every sending IP must have a reverse DNS record matching your sending domain. Contact your hosting provider to configure:
Configure DMARC to define handling policies and receive reports:
Dictates how many individual emails PowerMTA transmits before closing and reopening a connection. Keeping this value optimized reduces connection overhead. 6. Queue Management and Bounce Handling powermta configuration guide top
Email authentication is mandatory for inbox delivery in 2026. Inbox providers expect proper SPF, DKIM, DMARC, and PTR records before accepting large email volumes.
A well-configured PowerMTA server provides complete control over sender reputation and deliverability—capabilities that shared SMTP services simply cannot offer. By following this configuration guide, you will have built a robust, enterprise-grade email infrastructure capable of handling millions of messages daily while maintaining high inbox delivery rates. Every sending IP must have a reverse DNS
openssl genrsa -out /etc/pmta/dkim/private.key 2048 openssl rsa -in /etc/pmta/dkim/private.key -pubout -out /etc/pmta/dkim/public.key
This encodes binding and message ID into the bounce address for automated processing. System Time (NTP) <
: A clean, dedicated static IP is essential for building a sender reputation. Reverse DNS (rDNS/PTR) : Your IP must resolve back to your sending domain (e.g., ://yourdomain.com ). This is a critical check for ISPs like Gmail and Yahoo. System Time (NTP)
<domain gmail.com> # Delivery Settings max-delivery-rate 500/h # Throttle speed to warm up IP max-messages-per-connection 50 max-connections 10 # Bounce Handling dkim-sign yes dkim-identity @yourdomain.com dkim-selector your_selector dkim-private-key /etc/pmta/dkim.key