Whenever you modify the main configuration file or any linked external files, you must validate the syntax before restarting the service to avoid unexpected downtime. Step 1: Run a Syntax Check
These directives control how long PowerMTA holds onto an email if the receiving server faces a temporary failure (like a graylisting or full mailbox).
This is the file you edit to control PMTA’s behavior. After installation, you may also see auxiliary files like /etc/pmta/config-defaults (default settings read before the main config) and /etc/pmta/precached-domains for DNS pre‑caching. powermta config file link
Ensure your config points to your private key. Without DKIM, most of your mail will hit the spam folder.
max-smtp-out 100 max-message-rate 1000/h Use code with caution. 4. Accounting ( acct-file ) Whenever you modify the main configuration file or
: Enable secure delivery with enable-starttls yes . 4. Domain-Specific Rate Limiting
max-msg-rate 2/M enable-starttls yes ``` Use code with caution. Copied to clipboard 💡 Pro Tips for Configuration After installation, you may also see auxiliary files
<virtual-mta pmta-pool> smtp-source-host 192.0.2.10 203.0.113.20 198.51.100.30 max-msg-rate 1000/h dkim-sign yes domain-key default,example.com,/etc/pmta/example.pem </virtual-mta>
Essential for modern deliverability. DKIM Config Example: