Powermta Configuration Guide Top !full! File

A dedicated VPS or bare metal server (CentOS 7/8 or Ubuntu 20.04/22.04+) with at least 8GB RAM for high volumes.

PowerMTA automatically chooses the correct key based on the Sender or From header. For a single key covering multiple domains, a wildcard ( * ) can be used in the domain field.

Secure the HTTP interface so you can monitor real-time queue states and delivery success rates via a web browser.

_dmarc.example.com. TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com" powermta configuration guide top

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

PowerMTA’s automatic back‑off logic is a key deliverability feature. When a remote server returns a temporary error (4xx), PowerMTA increases retry intervals over time, preventing aggressive retries that can lead to long‑term throttling.

net.ipv4.ip_local_port_range = 1024 65535 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_fin_timeout = 30 net.core.somaxconn = 1024 net.core.netdev_max_backlog = 5000 A dedicated VPS or bare metal server (CentOS

Set 0.0.0.0/0 to always-allow-relaying no . Force remote users or external scripts to use SMTP authentication ( require-auth yes ).

: Generate a private key on the server and point to it in the config: domain-key 2026,*,/etc/pmta/dkim.key .

Before we dive into the configuration guide, let's cover some basics. PowerMTA is designed to be highly customizable and flexible, making it a popular choice for email service providers. It supports various features such as: Secure the HTTP interface so you can monitor

Verify PTR (Reverse DNS), SPF, and DKIM match the vMTA hostnames.

<feedback-loop-processor> command /usr/local/bin/handle-fbl.php </feedback-loop-processor>

When an email cannot be delivered immediately, PowerMTA moves it to a retry queue. If misconfigured, expired emails will clog your system and waste bandwidth on dead addresses.

tail -f /var/log/pmta/acct.csv | grep -v "dsn="

To build a reputation, you need to "warm up" your IPs. You can dictate the exact number of emails PMTA is allowed to send per day to an ISP.