Postfix Docker Image for Relay Domains

The image uses postfix to relay given domains to lmtp host's. if enabled (IMAP_HOST parameter) you can use sasl rimap authentication to authenticate against an imap server

Build image

git clone https://github.com/guitarmarx/postfix-image.git
cd postfix-image
docker build -t <imagename:version> .

Requirements

You need a running mysql database to add aliase and lmtp transport mappings

Quickstart

Docker (standalone)

docker run -d  \
    -p 25:25 \
    -e DB_HOST=<mysql host> \
    -e DB_USER=postfix \
    -e DB_PASS=postfix \
    -e DB_NAME=postfix \
    -e SMTPD_MILTERS="inet:<host1>:<port>, inet:<host2>:<port>" \
    -e DOMAIN=<your domain name> \
    --hostname `hostname` \
    -v <path>/cert.pem:/srv/cert/cert.pem:ro \
    -v <path>/privkey.pem:/srv/cert/privkey.pem:ro \
    -v <path>/fullchain.pem:/srv/cert/fullchain.pem:ro \
    <imagename>:<version>

Docker Swarm

docker run -d  \
    -p 25:25 \
    -e DB_HOST=<mysql host> \
    -e DB_USER=postfix \
    -e DB_PASS=postfix \
    -e DB_NAME=postfix \
    -e SMTPD_MILTERS="inet:<host1>:<port>, inet:<host2>:<port>" \
    -e DOMAIN=<your domain name> \
    --hostname "{{.Node.Hostname}}" \
    --mount type=bind,src=<path>/cert.pem,dst=/srv/cert/cert.pem,readonly \
    --mount type=bind,src=<path>/privkey.pem,dst=/srv/cert/privkey.pem,readonly \
    --mount type=bind,src=<path>/fullchain.pem,dst=/srv/cert/fullchain.pem,readonly \
    <imagename>:<version>

Configuration

Parameter	Function	Default Value
DOMAIN	(required) Server Domain	localhost.local
DB_HOST	(required) Mysql Database Host	localhost
DB_APP	(required) Mysql Database Name	postfix
DB_USER	(required) Mysql Database Host	postfix
DB_PASS	(required) Mysql Database Password	postfix
SMTPD_MILTERS	(required) Milter String	-
IMAP_HOST	(optimal) IMAP Host for rimap auth
IMAP_HOST	(optimal) IMAP Host for rimap auth
ENCRYPT_SETTING	(optimal) set's the parameter smtp_tls_security_level	may

Aliases and lmtp transportmapping

the image creates 2 tables when started:

• virtual_aliases (for aliases)
• transport (lmtp mapping)

To add aliases or lmtp transport mapping simply execute the following statements in your mysql database:

insert into transport (alias, email) VALUES ('<alias@domain>', 'email');
insert into transport (domain, destination) VALUES ('<domain>', 'lmtp:[<target host>]:2003');