Postfix as an internal mail-relay to an internet mail server, e.g Microsoft 365, Google Workspace, etc.
This image is NOT meant to be used as an open, insecure relay host and is NOT configured for that purpose.
Use case, haproxy ssl termination and acls to control access to the frontend using port 465, this container exposes port 25 on the container host, firewalld to only allow haproxy hosts access.
This route was chosen as it minimizes the amount of postfix configuration needed and we needed to be able to utilize postfix's header_checks to modify outgoing headers instead of just using haporxy to connect to the internet mail server.
Ubuntu Server LTS
Updated weekly from the official upstream Ubuntu LTS image
ca-certificates
curl
gnupg
jq
openssl
mailutils
postfix
postfix-pcre
procmail
tzdata
unzip
wget
see Ocie for more info
HOSTNAME - sets [ mydestination, myhostname ] and for header_checks
INTERNAL_DOMAIN - sets header_checks to remove internal/private domain/hostnames in header to the HOSTNAME
MY_NETWORKS - sets the IP/Networks that are allowed to connect
RELAY_HOST - set the relay destination, e.g smtp.gmail.com:465
25 - Plain-text
docker run --entrypoint /usr/sbin/ociectl -d bshp/mantis:latest --run
Add at end of your entrypoint script either of:
/usr/sbin/ociectl --run;
/usr/sbin/postfix -c /etc/postfix start-fg;
VERSION = Ubuntu version to build, e.g 22.04, 24.04
docker build . --pull --build-arg VERSION=22.04 --tag YOUR_TAG