Docker postfix + opendkim

Create container without private key

If you don't have private key for opendkim signature, dont' worry, it will be auto-generated.

docker run \
	-d \
	-e DKIM_DOMAIN=example.com \
	-e DKIM_SELECTOR=mail \
	glavich/docker-postfix:latest

On container generation, DNS TXT setting will be dumped to logs. You can see it by typing: docker logs CONTAINER_ID (for example docker logs 5bcc4f4f186e or docker logs amazing_banach).

Create container with private key

If you already have your own private key for opendkim signature, just add it to container folder: /etc/opendkim/keys/. Be sure to name it SELECTOR.private (if selector is mail, then name file mail.private).

docker run \
	-d \
	-e DKIM_DOMAIN=example.com \
	-e DKIM_SELECTOR=mail \
	-v $(pwd)/mail.private:/etc/opendkim/keys/mail.private \
	glavich/docker-postfix:latest

Generate private key with opendkim-genkey

With following command, private key (mail.private) and dns txt setting (mail.txt)file, will be generated in your current folder.

docker run \
	--rm \
	-v $(pwd):/x \
	glavich/docker-postfix:latest \
	opendkim-genkey \
		-b 1024 \
		-d example.com \
		-D /x \
		-h sha256 \
		-r \
		-s mail \
		-v

More on opendkim-genkey options can be read here: http://www.opendkim.org/opendkim-genkey.8.html