Powermta Configuration Guide Top Upd Access

PowerMTA can process millions of messages per hour, but sending too fast will trigger immediate rate-limiting or blocks from major ISPs. You must throttle your global outbound traffic to prevent server resource exhaustion. Essential Performance Directives

Register your sending IPs with Microsoft SNDS, Yahoo FBL, and other major providers. Route the incoming Abuse Reporting Format (ARF) emails back into an automated processing mailbox to immediately unsubscribe complaining users. 7. Performance Tuning and Optimization

deliver-bounces no log-bounces yes # Example rule to classify a specific bounce regex "5\.2\.2" action delete Use code with caution. B. FBL Integration

Configure bounce processing to classify hard vs soft bounces.

disk-queue /var/spool/powermta memory-pool-buffer-size 2m powermta configuration guide top

<rejectlog-file /var/log/pmta/reject.log> records c,r max-size 100M </rejectlog-file>

The heart of PowerMTA lies in the domain directives. This is where you tell the software how to handle specific receivers (like Gmail, Outlook, or Yahoo).

<source *> # Deny all by default allow-relay no </source>

The <acct‑file> directive writes delivery events (successes, failures, bounces) to a CSV file that an external processor can consume. A minimal accounting file configuration: PowerMTA can process millions of messages per hour,

Proper authentication is non‑negotiable. Without it, your mail will be flagged as spam or rejected outright.

Assign specific CPU cores to specific domains to prevent cross-domain blocking.

Listeners define how PowerMTA accepts messages from your application or another MTA:

This defines how many total outgoing connections PMTA will make. Start here. Route the incoming Abuse Reporting Format (ARF) emails

How many times to retry a single message before giving up.

| Mistake | Consequence | Fix | | :--- | :--- | :--- | | max-smtp-out 1000 on a 2GB VM | Connection flooding, kernel panic | Set to 250 max for small VMs | | No domain * block | Wildcard throttling fails | Always define a default domain | | max-msg-per-connection 0 | Never closes connections | Set to 50-200 | | Ignoring initial-pts | Getting blocked for "hammering" | Set initial-pts 60 minimum | | Running as root | Security breach | Use process-user |

# Virtual MTA Definition for IP 1 smtp-source-ip 192.0.2.1 host-name ://yourdeliverydomain.com # Virtual MTA Definition for IP 2 smtp-source-ip 192.0.2.2 host-name ://yourdeliverydomain.com # Grouping for Load Balancing virtual-mta vmta-ip1 virtual-mta vmta-ip2 Use code with caution. 3. Email Authentication (SPF, DKIM, and DMARC)