Knowledge base
smtp-default-ipscriticalWritten by the HubdirectiveList of addresses submitted mail is sent from — and, when set, it replaces the intake mapping rather than backing it up.smtp-ipcriticalWritten by the HubdirectiveSemicolon-separated list of local addresses on which mail is accepted — and, by that act, the addresses it will be sent from.smtp-mappable-ipscriticalWritten by the HubdirectiveRanges of local addresses for which mail submitted on an address is also sent from that address.smtp-portimportantWritten by the HubdirectivePort or ports on which mail is accepted, with STARTTLS available if a certificate is configured.smtp-hostnameWritten by the HubdirectiveHostname the SMTP server presents in its banner, overriding the system hostname.smtp-unmappable-ipsWritten by the HubdirectiveRanges taken back out of the mappable set — loopback and private addresses by default.smtp-defaultipdirectiveAccepted by the binary; singular variant, undocumented and absent from the stock config.smtp-defaultipsdirectiveAccepted by the binary; neither printed by –help nor present in the stock config.smtp-proxydirectiveAddress ranges whose connections begin with a PROXY header carrying the real client address.Why mail leaves from the address it arrived oncriticalWritten by the HubmechanismMail handed to the built-in SMTP server goes out from the address it was handed to — unless a default address list is configured, which replaces the rule entirely.Named groups of sending addressesimportantWritten by the HubAPI endpointCreates and lists the address pools that a message can ask for by name.Addresses that belong to us but live elsewhereAPI endpointThe register of sending addresses reached through another machine — a NAT or a proxy — rather than bound locally.Which addresses belong to which poolAPI endpointLists pool membership; every write form we tried was refused, and the console uses its own path for this.list-ipsstartup flagPrints the local addresses available for sending, then exits.Proxiesimportantconsole screenSending from addresses the machine does not have, through a NAT or a proxy that owns them.IP PoolsimportantWritten by the Hubconsole screenNamed groups of sending addresses — and the screen that enforces one pool per address.ipsimportantdatabase tableOne row per sending address, each with its own broker, exchange and queue — which is how a specific address can be given its own stream of mail.mtanamesimportantWritten by the Hubdatabase tableThe name each sending address announces in the SMTP greeting.pool_ipsimportantWritten by the Hubdatabase tableOne row per address in a pool; an address may appear at most once.poolsimportantWritten by the Hubdatabase tableNamed groups of sending addresses, referenced by name in a message's job data.external_mtasdatabase tableAddresses that are not on the machine: the engine binds locally, connects to a proxy, and mail leaves from an address the proxy owns.protocoldatabase fieldThe protocol spoken to the proxy that owns the public address.envelopecriticalWritten by the Hubmessage propertyThe return address used in MAIL FROM — where bounces and delivery notifications arrive, and what receivers check against SPF.ipscriticalWritten by the Hubmessage propertyA list of sending addresses this message is allowed to use, overriding the node's own arrangement.poolimportantWritten by the Hubmessage propertyThe name of an address pool the message should be sent from.x-mq-ipcriticalemail headerNames an address the message may be sent from; repeat the header to offer several.x-mq-envelopeimportantemail headerSets the envelope address, overriding what the message headers imply.x-mq-poolimportantemail headerNames the pool the message should be sent from.The sender was refusedcriticaldelivery stateThe receiver refused our envelope address before the recipient was mentioned.The sending address could not be usedimportantdelivery stateThe engine could not bind to the local address it was told to send from.The extended greeting was refusedimportantdelivery stateThe receiver rejected our EHLO — often the first place a reputation problem shows.The plain greeting was refuseddelivery stateThe same refusal as ehlo, on a server too old for the extended greeting.