Lightweight SMTP relay using msmtpd as a Docker image.
Tip
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- Run as non-root user
- Latest msmtp/msmtpd release compiled from source
- Bind to unprivileged port
- Multi-platform image
git clone https://github.com/crazy-max/docker-msmtpd.git
cd docker-msmtpd
# Build image and output to docker (default)
docker buildx bake
# Build multi-platform image
docker buildx bake image-all
Registry | Image |
---|---|
Docker Hub | crazymax/msmtpd |
GitHub Container Registry | ghcr.io/crazy-max/msmtpd |
Following platforms for this image are available:
$ docker run --rm mplatform/mquery crazymax/msmtpd:latest
Image: crazymax/msmtpd:latest
* Manifest List: Yes
* Supported platforms:
- linux/amd64
- linux/arm/v6
- linux/arm/v7
- linux/arm64
- linux/386
- linux/ppc64le
- linux/s390x
TZ
: Timezone assigned to the container (defaultUTC
)PUID
: Daemon user id (default1500
)PGID
: Daemon group id (default1500
)SMTP_HOST
: SMTP relay server to send the mail to. requiredSMTP_PORT
: Port that the SMTP relay server listens on. Default25
or465
if TLS.SMTP_TLS
: Enable or disable TLS (also known as SSL) for secured connections (on
oroff
).SMTP_STARTTLS
: Start TLS from within the session (on
, default), or tunnel the session through TLS (off
).SMTP_TLS_CHECKCERT
: Enable or disable checks of the server certificate (on
oroff
). They are enabled by default.SMTP_AUTH
: Enable or disable authentication and optionally choose a method to use. The argumenton
chooses a method automatically.SMTP_USER
: Set the username for authentication. Authentication must be activated with theSMTP_AUTH
env var.SMTP_PASSWORD
: Set the password for authentication. Authentication must be activated with theSMTP_AUTH
env var.SMTP_DOMAIN
: Argument of theSMTP EHLO
command (defaultlocalhost
)SMTP_FROM
: Set the envelope-from address. Supported substitution patterns can be found here.SMTP_SET_FROM_HEADER
: When to set a From header. Can beauto
,on
oroff
(defaultauto
)SMTP_SET_DATE_HEADER
: When to set a Date header. Can beauto
oroff
(defaultauto
)SMTP_REMOVE_BCC_HEADERS
: Controls whether to remove Bcc headers. Can beon
oroff
(defaulton
)SMTP_UNDISCLOSED_RECIPIENTS
: When set, the original To, Cc, and Bcc headers of the mail are removed and a single new header lineTo: undisclosed-recipients:;
is added. Can beon
oroff
(defaultoff
)SMTP_DSN_NOTIFY
: Set the condition(s) under which the mail system should send DSN (Delivery Status Notification) messages as comma separated values. Available values areoff
,never
,failure
,delay
andsuccess
(defaultoff
)SMTP_DSN_RETURN
: Controls how much of a mail should be returned in DSN (Delivery Status Notification) messages. Can beheaders
,full
oroff
(defaultoff
)
💡
SMTP_USER_FILE
andSMTP_PASSWORD_FILE
can be used to fill in the value from a file, especially for Docker's secrets feature.
💡 More info: https://marlam.de/msmtp/msmtp.html
2500
: SMTP relay port
Docker compose is the recommended way to run this image. You can use the following docker compose template, then run the container:
docker compose up -d
docker compose logs -f
To install on a Kubernetes cluster, you can use the following kubernetes deployment template, then create the deployment:
kubectl apply -f deployment.yaml
You can also use the following minimal command:
$ docker run -d -p 2500:2500 --name msmtpd \
-e "SMTP_HOST=smtp.example.com" \
crazymax/msmtpd
Recreate the container whenever I push an update:
docker compose pull
docker compose up -d
Want to contribute? Awesome! The most basic way to show your support is to star the project, or to raise issues. You can also support this project by becoming a sponsor on GitHub or by making a PayPal donation to ensure this journey continues indefinitely!
Thanks again for your support, it is much appreciated! 🙏
MIT. See LICENSE
for more details.