Knowledge base
smtp-connections-outimportantWritten by the HubdirectiveHow many connections to receiving servers the engine may hold open at once, across all domains.smtp-connectionsWritten by the HubdirectiveUpper limit on all SMTP connections the engine holds, incoming and outgoing together.smtp-connections-inWritten by the HubdirectiveHow many clients may be connected to the intake at once.smtp-threadsWritten by the HubdirectiveHow many threads handle incoming SMTP traffic; each binds its own socket per address.smtp-timeoutdirectiveSeconds the intake waits for a client to say something before closing the session.activecounterThe connections actually sending — computed, not measured.connectionscounterAll outgoing SMTP connections the node holds, in any state.connectscounterHow many times the engine had to open a fresh SMTP connection.reusescounterMessages that went down a connection already open — the measure of how well pipelining works.connectingcounterConnections in handshake, or open but with nothing to send yet.idlecounterOpen connections with nothing to send, kept for the next message.connection_minmessagesimportantWritten by the Hubdatabase fieldHow much work an existing connection must be given before the engine decides to open a second one.domain_maxconnectingimportantWritten by the Hubdatabase fieldHow many connections to one domain may be in the middle of being established at once — shipped at one.flagsimportantWritten by the Hubdatabase fieldA bit field holding the console's behaviour switches — the ones with no column of their own.meaningfulimportantWritten by the Hubdatabase fieldThe companion mask to flags: one bit per switch, saying whether this profile decides it at all.securityimportantdatabase fieldHow hard the engine tries to encrypt: never, opportunistically, required, or required with strict certificate checks.connection_maxidletimeWritten by the Hubdatabase fieldSeconds an unused connection is held open before being closed.connection_maxmessagesWritten by the Hubdatabase fieldHow many messages may be sent down one SMTP connection before it is closed and reopened.domain_maxidleWritten by the Hubdatabase fieldHow many established but unused connections to a domain are kept for reuse.timeout_connectdatabase fieldRepresentative of the seventeen per-stage timeouts: how long the engine waits at each step of an SMTP conversation.connection_featurestimedatabase fieldSeconds the engine caches what a receiving server announced in its greeting.securityWritten by the Hubmessage propertyHow hard to insist on encryption for this message: optional, opportunistic, required or verified.The connection could not be madecriticaldelivery stateTCP connection to the receiving server failed or timed out.The connection went quietdelivery stateAn established connection stopped responding while the message was in flight.The greeting never camedelivery stateThe receiving server accepted the connection but did not greet us in time.Connection vanisheddelivery resultThe connection was broken before the exchange finished.