On Sun, Jan 24, 2021 at 06:30:43PM -0600, P. Ik. wrote: > 172.17.0.* are the container ip's > .1 is the postfix host
You have *source NAT* between the Internet and your MTA, so that all
external connections appear to originate from the same source. With
such a configuration, you MUST NOT trust any sources by IP address.
Either remove the NAT, allowing the VM to see and route to public IPs,
or require authentication (TLS client cert or SASL) for all outbound
email.
--
Viktor.
