semrekkers / mailsrv

An easy-to-setup, single container mail server that supports SMTP, POP3 and IMAP

Mailsrv

Mailsrv (mailserver) is an easy-to-setup, single container mail server that supports SMTP, POP3 and IMAP. Under the hood it uses Postfix, Dovecot and OpenDKIM to handle your mail fast and secure.

Requirements

The only things you need are a TLS certificate and a MySQL database! Configuration (of Postfix, Dovecot, etc) is automatically done for you.

Getting started

This will only take a few minutes!

Step 1

Setup your database. If you don't have a running instance of MySQL yet, use Docker to set one up: docker run -d --name mysql-server -e MYSQL_ROOT_PASSWORD=<new password> mysql.

Create a database for your email accounts (e.g. mail_accounts). Then, execute the database/seed.sql script. If you just created a new instance of MySQL from above, you can access your instance using docker exec -it mysql-server mysql -u root -p and type in your password. If you want, you can just copy/paste the contents of database/seed.sql into the monitor.

Step 2

Setup your email domains, run INSERT INTO virtual_domains (name) VALUES ('<your domain>'); for each domain you want to use (lookup the id's for the next step).

Step 3

Setup your email accounts. run INSERT INTO virtual_users (domain_id, email, password) VALUES (<domain id>, '<email>', ENCRYPT('<password>', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16))));.

Step 4

Create a TLS certificate (it's better to use Let's Encrypt): openssl req -x509 -newkey rsa:2048 -keyout privkey.pem -out cert.pem -nodes -days 365.

Step 5

Run mailsrv!

docker run -d --name mail-server \
    --link mysql-server \
    -v /path/to/tls/certificates:/etc/ssl/mailsrv \
    -e MYSQL_HOST=mysql-server \
    -e MYSQL_DB=mail_accounts \
    -e MYSQL_USER=root \
    -e MYSQL_PASSWORD=<MySQL root password> \
    -p 25:25 -p 465:465 -p 587:587 -p 993:993 -p 995:995 \
    semrekkers/mailsrv

NOTE: From a security point of view, this is not a good practise. You must have some experience/knowledge about TLS, SMTP, IMAP, POP3, DKIM, SPF and DMARC to use this Docker image correctly.

Environment variables

Name	Description	Default
MAIL_TLS_DIR	Base directory of your TLS certificate.	/etc/ssl/mailsrv
MAIL_CERT	TLS certificate to use.	$MAIL_TLS_DIR/cert.pem
MAIL_KEY	Private key to use.	$MAIL_TLS_DIR/privkey.pem
MYSQL_HOST	MySQL host.	Required
MYSQL_DB	MySQL database.	Required
MYSQL_USER	MySQL username.	Required
MYSQL_PASSWORD	MySQL password.	Required
MAIL_DKIM_SELECTOR	DKIM selector.	Random string
MAIL_DKIM_KEY	DKIM private key.	/etc/opendkim/privkey.pem

Details

What you typically only need is a (valid) TLS certificate, a MySQL database and a DKIM key pair. You must configure SPF, DKIM (DNS record) and DMARC yourself. This image uses a system-wide DKIM key pair to sign all outgoing mail.

Why this image?

If you configure it correctly, you have a nice and small email server that can handle most email traffic for personal or small business use. You can easily replace/update it because you don't have to touch any configuration file, all your email accounts are stored in one database.

How about spam filters?

Coming soon (maybe?)

Contributions and issues

Please open up an issue on GitHub!