Knowledge base
<domain>criticalConfiguration blockThe largest PowerMTA block and the main one among those the Hub generates itself.<source>criticalConfiguration blockRules for whoever connects to submit: whether relaying is allowed, which control headers to honor, which limits apply and whether authentication is required.<virtual-mta>criticalConfiguration blockOne outgoing address with a greeting name and its own limits — the identity the receiving server sees.GlobalcriticalConfiguration blockLines that belong not to a queue but to the instance itself: ceilings, the spool, listeners, logging, the license and the web monitor.<acct-file>Configuration blockOne accounting stream: which records and fields it carries, where it is written, how often it is rotated and how long it is kept.<bounce-processor>Configuration blockThe block enables parsing inbound messages for bounces; it catches them by a nested address list and writes accounting records of type rb.<dns>Configuration blockThe DNS precache block: a file with a list of domains, a ceiling on their number and a refresh schedule. Resolvers are set outside the block.<domain-key-list>Configuration blockA named list of domain-key lines at node level: a message selects it with the x-dkim-options header with key-list=, and the key is searched only in that list.<feedback-loop-processor>Configuration blockThe block enables parsing inbound messages for complaints; it catches them by a nested address list and writes accounting records of type f.<pattern-list>Configuration blockRegular expressions matched against the sender, the recipient or a header to choose a sending address.<proxy>Configuration blockA named block with the proxy address and the external sending address; both lines are mandatory, and there can be several blocks.<smtp-listener>Configuration blockSettings that apply to connections on one address and port: encryption, rights through a named source, behavior when the ceiling is reached.<smtp-pattern-list>Configuration blockPatterns matched against receiver responses — the very trigger that backoff mode reacts to.<spool>Configuration blockThe directory where the engine keeps message files while they wait for delivery; there can be several directories, each with its own priority and free space threshold.<virtual-mta-pool>Configuration blockSeveral addresses addressed as one, with rotation among them.<address-list>Configuration blockA named list is attached by its name; an unnamed one lives inside a bounce or complaint processor and selects mail for parsing.<email-patterns>Configuration blockA block with pattern files, nested inside a bounce or complaint processor; it has two lines.<include-config>Configuration blockThe same as include with an address, but lets you set request headers — for example, authorization.<prometheus-listener>Configuration blockThe block opens a port on the node from which the monitoring system collects metrics in Prometheus format; a node can have only one such block.<signals>Configuration blockThe block enables sending accounting data to the vendor’s service; the engine chooses the data composition, the scope is set with a separate line.<smtp-user>Configuration blockOne block, one login: what confirms the login and which named source gives it rights; declared at the root of the file.<source-group>Configuration blockGathers sources into a group so that inbound connection limits apply to them together; members name the group on their side.<transmissions-api-listener>Configuration blockThe address, port and encryption for submitting messages over HTTP.<transmissions-api>Configuration blockAccess keys, the request size limit and logging for submitting mail over HTTPS; declared once at the root of the file.<vault>Configuration blockThe block describes the connection to Vault; from there the node takes signing keys, certificates and their passwords without keeping them in its files.<inline-seeding>Configuration blockThe block enables seeding campaigns with the vendor’s addresses; it requires a key and a paid subscription and recommends a restart after adding.<rewrite-list>Configuration blockA named list of rules; attached to a source by name, and all messages from there pass through it.<signals-filter>Configuration blockA block with rules by sender domain; attached to the scope by name, and anything not matched is considered disabled.