Demo
Demo

Knowledge base

smtp-default-ips verifiedcriticalWritten by the Hub

Sending addresses used instead of mapping

in the configuration this is a linesmtp-default-ips:

List of addresses submitted mail is sent from — and, when set, it replaces the intake mapping rather than backing it up.

Values

Values
local addresses separated by ;
Default
· taken from the build
applying
restart required
where it can be set
in the config file · with a startup flag · as an environment variable

In detail

The name suggests a fallback for messages that have no address of their own. The behaviour is different, and it was worth measuring. With the list empty, mapping applies and each message leaves from the address it was submitted on. With 178.253.53.90 in the list, six messages submitted across two other addresses all left from .90. With .90;.83 in the list, the same messages came out spread across those two, unrelated to where each had been submitted. So: setting this directive switches the mapping off and makes the list the sending pool for everything the SMTP server accepts. That is a useful thing to have — it is how one forces all intake onto a chosen set of addresses — but it is not what "default" implies, and a node configured by someone expecting a fallback will send from the wrong addresses without any error.

What happens if you get it wrong

Set by someone expecting a fallback.Every submitted message leaves from the listed addresses, including messages submitted elsewhere on purpose. Measured, not inferred.verified by experiment · inference
Lists an address the node does not have.Binding for that address fails; mail either takes another address from the list or fails to send.inference