This is the heart of your PowerMTA system. The key to a maintainable and powerful configuration is to not treat it as a monolithic file but as a modular, inheritable set of rules. Keep your configuration "DRY" (Don't Repeat Yourself) and let specific rules override general ones.
<domain outlook.com hotmail.com live.com> max-smtp-out 10 max-smtp-out-per-ip 2 max-messages-per-connection 20 concurrency 10 resolve-interval 600 </domain> powermta configuration guide top
A VirtualMTA (vMTA) maps a specific source IP address to a specific hostname. Splitting traffic across multiple vMTAs prevents a bad sending campaign on one IP from burning your entire pool. Setting Up a VirtualMTA Group This is the heart of your PowerMTA system
This guide walks you through every step, from initial server preparation to advanced topics such as virtual MTAs, signature‑based authentication, real‑time monitoring, and cluster‑ready architecture. By the end, you will have a battle‑tested, production‑ready setup that follows industry best practices. All configuration snippets are ready to be dropped into your own /etc/pmta/config file. <domain outlook
Ensure file permissions for private DKIM keys are restricted to the pmta user. To apply changes, restart the daemon via your terminal: systemctl restart pmta Use code with caution.
<domain yahoo.com> max-smtp-out 15 max-smtp-out-per-ip 3 max-messages-per-connection 50 concurrency 15 <limits> throttle 500/minute </limits> </domain>
# Week 1 <bind source-vmta="newip1" destination-domain="*"> <limits> throttle 500/hour </limits> max-smtp-out 5 </bind>