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Demo

Knowledge base

smtp-unmappable-ips verifiedWritten by the Hub

Addresses excluded from mapping

in the configuration this is a linesmtp-unmappable-ips: 127.0.0.0/8,192.168.0.0/16

Ranges taken back out of the mappable set — loopback and private addresses by default.

Values

Values
addresses and ranges
Default
127.0.0.0/8,192.168.0.0/16 · 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

Exists because the mappable range ships wide open: sending from 127.0.0.1 or a private address would be nonsense, so those are excluded. Tested on the stand by adding a real public address to the exclusion list: with smtp-default-ips empty, mail submitted there still went out from it, so exclusion alone did not redirect anything. Recorded as observed rather than explained — see the open question.