Sample Powermta Configuration File Hot • Premium

# ------------------------------------------------------------ # PowerMTA Hot Configuration File v4.5+ # Optimized for: 500k - 2M emails/hour # Key features: Multi-IP warmup, ISP throttling, DKIM, Feedback Loop # ------------------------------------------------------------ These set the base behavior for all domains. smtp-service { max-message-size 50M max-connections 5000 max-clients 5000 max-data-connections 2000 connection-backlog 500 tcp-nodelay true tcp-keepalive true dns-timeout 30 dns-retries 2 } ---------- PERFORMANCE TUNING (HOT) ---------- Increase concurrency and reduce latency. processes 8 # One per CPU core max-smtp-out 2000 # Total outgoing connections max-errors-per-domain 20 max-errors-per-ip 10 max-no-answer 10 max-unknown-domain 5 max-per-host-out 100 # High concurrency per ISP max-per-ip-out 240 # Aggressive IP usage queue-retry-period 600 max-queue-size 5M max-retries 48 max-retry-interval 14400 # 4 hours max retry retry-interval 900 # Start retry after 15 min vmta-expansion true vmta-pool-expansion true ---------- BOUNCE & FEEDBACK PROCESSING ---------- Hot config = fast bounce classification. bounce { dsn-retries 5 dsn-wait 3600 lazy-bounce-interval 3600 max-bounce-rate 10% bounce-catcher <bounces@yourdomain.com> }

feedback-loop { enabled true folder /var/log/pmta/fbl process-cmd "/usr/bin/php /etc/pmta/fbl-handler.php" } To avoid disk I/O bottleneck, mount /var/log/pmta as tmpfs. log-stats { file /var/log/pmta/stats.log format "csv" interval 300 keep 30 } sample powermta configuration file hot

vmta pool-warmup { source-hash true max-msg-rate 2000/minute bind-ip-range 192.0.2.31-192.0.2.40 # New IPs in warmup } Route different streams to different pools. vmta main-sender { auto-warmup true pool pool-high-volume dkim-signature "main" # See DKIM section below always-allow-vmta-domain true max-smtp-out 200 queue-type shared } In the world of high-volume email delivery, PowerMTA

Introduction: What Makes a PowerMTA Config "Hot"? In the world of high-volume email delivery, PowerMTA (PMTA) by SparkPost is the gold standard for MTA (Mail Transfer Agent) software. However, a standard, out-of-the-box configuration will not survive a modern sending environment. To handle millions of emails per hour, you need a "hot" configuration file —one that is aggressively tuned for throughput, DKIM signing, bounce handling, and ISP throttling. and ISP throttling.

pmta send test --recipients=1000 --rate=100/minute Monitor queues in real-time: