Sample Powermta Configuration File Hot Jun 2026

<domain *> max-smtp-out 20 max-connect-rate 5/m max-msg-per-connection 100 max-msg-rate 1000/h bounce-after 4d12h retry-after 10m

: This sets an hourly volume ceiling. For warm, high-reputation IP addresses, this number can scale up significantly. For brand-new IPs undergoing an IP warming cycle, drop this value down to 200 or 500 messages per hour and scale up incrementally over several weeks. 4. The Backoff Engine ( )

; DKIM signing (using a key file per domain) dkim-domain example.com 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

# Virtual MTA for a specific IP smtp-source-ip 1.2.3.4 host-name ://yourdomain.com domain-key selector1, yourdomain.com, /etc/pmta/dkim.private.key # Virtual MTA Pool for load balancing multiple IPs virtual-mta vmta1 virtual-mta vmta2 Use code with caution. Copied to clipboard 4. Domain Directives (Rate Limiting) Domain Directives (Rate Limiting) If you want, I

If you want, I can:

Microsoft relies heavily on temporary 421 SMTP deferrals to control incoming volume. If your server ignores these warnings and continues hammering their network at the same speed, your IP will be escalated to a hard 550 permanent block. you can rotate your sending identity.

acct-file /var/log/pmta/acct.csv acct-fields *,dlvSourceIp,vmtaPool,rcpt,bounceCat

By grouping IPs into virtual-mta pools, you can rotate your sending identity. If one IP gets "cold" (low reputation), you can shift traffic to another pool without rewriting your entire application logic. 4. Advanced Bounce Handling

Are you currently encountering any specific (like 421 RP-001 or 550 SC-001 ) in your delivery logs?

Ensure SPF, DKIM, DMARC, and rDNS are perfectly set up before applying these settings. Sample PowerMTA Hot Configuration File ( /etc/pmta/config )