To avoid being blocked by major ISPs like Gmail or Yahoo, you can set specific limits on how fast your server sends mail.
Check out the snippet below for the core /etc/pmta/config structure! ⬇️
smtp-listener 0.0.0.0:2525 smtp-service yes default-virtual-mta pmta-vmta-pool sample powermta configuration file hot
# Network settings smtp_port = 25 submission_port = 587
<source 0/0> always-allow-relaying yes process-x-virtual-mta yes # Allows the injection source to pick the VMTA Use code with caution. Copied to clipboard Best Practices for High-Volume Delivery To avoid being blocked by major ISPs like
: Allows aggressive connection thresholds ( max-smtp-out 100 ) and high hourly volumes if your domain has a strong reputation and valid DKIM alignment.
: Ensure that every IP listed in your smtp-source-ip directives accurately resolves back to the host-name listed within that same Virtual MTA block. If you need to adjust this template further, let me know: How many dedicated IP addresses you are using? What average volume of email you plan to send per hour? Copied to clipboard Best Practices for High-Volume Delivery
max-msg-rate 500/m # Global limit: 500 messages per minute max-msg-rate 5/m # Throttled limit for Gmail specifically max-errors-per-connection 1 Use code with caution. Copied to clipboard 5. Web Monitoring Console