crowly/sendmail-cyrus repository overview

Sendmail/Cyrus Email

This image is based on CentOS, and provides SMTP and IMAP services using sendmail and Cyrus.

In order to keep as close the running things the way CentOS would normally, systemd is used to invoke both sendmail and cyrus-imapd.

SSL

On first run the image create and uniqe set of self signed ssl certs for sendmail and cyrus, so you can use ssl be default.

Mount Points

The image has a number of mount points so you can use another volume for hypervisor storage to store your email, or configuration settings. If you mount a blank external director for any of these mount points they will get populated on first start.

/var/spool/imap /var/lib/imap /var/spool/mqueue /etc/mail /etc/pki/tls/certs/

Systemd

As the image uses systemd it does need access to cgroups, this is done by mounting cgroups from the hypervisor. This does allow systemd inside the container to see things outside the container, so you should give the implications of this some thought before using this image.

NSS/Pam

The pgsql version of the image uses PostgreSQL for its users, making use of pam and nss. This allows the image to make use of a PostgreSQL docker container for storing users/password and groups so the mail server image does not need to.

Usage

docker run -v /sys/fs/cgroup:/sys/fs/cgroup:ro -v /tmp/$(mktemp -d):/run -e "container=docker" -e NSS_PG_USER_PASSWD=pgsql_pw -e NSS_PG_HOST=pg_host