EXIM4 Helm

A Helm chart to provide a exim4 deployment, exim4 (MTA) running as a smarthost.

The MTA is based on Exim4. The Image was inspired by the Docker Image from imixs/exim4. The Docker image is based on debian:jessie.

Prerequisites

• Kubernetes 1.16+
• Helm 3.7+

Add Helm Repository

helm repo add exim4 https://mb-wali.github.io/exim4-helm
helm repo update

Installing the Chart

Basic Installation

helm install [RELEASE_NAME] exim4/exim4 \
  --namespace [NAMESPACE] \
  --create-namespace \
  --wait

Installation with Custom Values

helm install exim4 exim4/exim4 \
  --namespace mail \
  --create-namespace \
  --wait \
  --set secrets.EXIM_SMARTHOST='localhost' \
  --set secrets.EXIM_PASSWORD='passw0rd' \
  --set secrets.EXIM_ALLOWED_SENDERS='*'

Configuration

The following environment variables can be configured via Helm values:

Environment Variable	Description	Default
EXIM_SMARTHOST	Address of the target mail server	(required)
EXIM_PASSWORD	Password for authenticating to the remote smarthost	(required if needed)
EXIM_ALLOWED_SENDERS	Allowed sender IP addresses or CIDR networks	172.17.0.0/24:127.0.0.1
EXIM_MESSAGE_SIZE_LIMIT	Overrides the default message size limit (default is 50M). Example: 255M	255M

Debugging

Once the pod is running, you can troubleshoot or test it with the following commands:

# Start an interactive shell in the Exim4 pod
kubectl exec -it exim4-6ff546fb9f-ff47m -- bash

# Example: Send a test email
echo "This is test" | mail -s "The subject" reciever@myhost.com -aFrom:sender@myhost.com

Usage

Use the deployed Exim4 instance as your SMTP relay from other services within the cluster:

SMTP_HOST=exim4.mail.svc.cluster.local

Local Installation for Testing

helm install exim4 Charts/exim4/ \
  --namespace mail \
  --create-namespace \
  --wait \
  --dry-run