A fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.). Only configuration files, no SQL database. Keep it simple and versioned. Easy to deploy and upgrade. [Documentation][documentation::web] via MkDocs. [Why this image was created.](https://tvi.al/simple-mail-server-with-docker/).
If you have issues, read the full `README`**and** the [documentation][documentation::web] **for your version** (default is `edge`) first **before opening an issue**. The issue tracker is for issues, not for personal support.
- [Dovecot](https://www.dovecot.org) for SASL, IMAP (or POP3), with LDAP Auth, Sieve and [quotas](https://docker-mailserver.github.io/docker-mailserver/edge/config/user-management/accounts#notes)
**Note:** You'll need to deactivate some services like ClamAV to be able to run on a host with 512MB of RAM. Even with 1G RAM you may run into problems without swap, see [FAQ](https://docker-mailserver.github.io/docker-mailserver/edge/faq/#what-system-requirements-are-required-to-run-docker-mailserver-effectively).
[CI/CD](https://github.com/docker-mailserver/docker-mailserver/actions) will automatically build, test and push new images to container registries. Currently, the following registries are supported:
**Make sure to get the `setup.sh` that comes with the release you're using**. Look up the release and the git commit on which this release is based upon by selecting the appropriate tag on GitHub. This can done with the "Switch branches/tags" button on GitHub, choosing the right tag. This is done in order to rule out possible inconsistencies between versions.
- these files supports [only simple `VAR=VAL`](https://docs.docker.com/compose/env-file/)
- don't quote your values
- variable substitution is *not* supported (e.g. `OVERRIDE_HOSTNAME=$HOSTNAME.$DOMAINNAME`).
- Variables in `.env` are expanded in the `docker-compose.yml` file **only** and **not** in the container. The file `mailserver.env` serves this case where environment variables are used in the container.
- If you want to use a bare domain (host name = domain name), see [FAQ](https://docker-mailserver.github.io/docker-mailserver/edge/faq#can-i-use-nakedbare-domains-no-host-name)
If you'd like to use SELinux, add `-Z` to the variable `SELINUX_LABEL` in `.env`. If you want the volume bind mount to be shared among other containers switch `-Z` to `-z`
If you're seeing error messages about unchecked error, please **verify that you're using the right version of `setup.sh`**. Refer to the [Get the tools](#get-the-tools) section and / or execute `./setup.sh help` and read the `VERSION` section.
In case you're using LDAP, the setup looks a bit different as you do not add user accounts directly. Postfix doesn't know your domain(s) and you need to provide it when configuring DKIM:
When keys are generated, you can configure your DNS server by just pasting the content of `config/opendkim/keys/domain.tld/mail.txt` to [set up DKIM](https://mxtoolbox.com/dmarc/dkim/setup/how-to-setup-dkim). See the [documentation](https://docker-mailserver.github.io/docker-mailserver/edge/config/best-practices/dkim/) for more details.
If you'd like to change, patch or alter files or behavior of `docker-mailserver`, you can use a script. See the [documentation](https://docker-mailserver.github.io/docker-mailserver/edge/config/advanced/user-patches/) for a detailed explanation.
We are currently providing support for Linux. Windows is _not_ supported and is known to cause problems. Similarly, macOS is _not officially_ supported - but you may get it to work there. In the end, Linux should be your preferred operating system for this image, especially when using this mailserver in production.
#### Support for Multiple Domains
`docker-mailserver` supports multiple domains out of the box, so you can do this:
If you got any problems with SPF and/or forwarding mails, give [SRS](https://github.com/roehling/postsrsd/blob/master/README.md) a try. You enable SRS by setting `ENABLE_SRS=1`. See the variable description for further information.
See the [documentation](https://docker-mailserver.github.io/docker-mailserver/edge/config/security/understanding-the-ports/) for further details and best practice advice, **especially regarding security concerns**.
This example provides you only with a basic example of what a minimal setup could look like. We **strongly recommend** that you go through the configuration file yourself and adjust everything to your needs. The default [docker-compose.yml](./docker-compose.yml) can be used for the purpose out-of-the-box, see the [usage section](#usage).
