alpine approach

Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:bookworm
+FROM alpine:3.21.0
 
 LABEL Maintainer="Wolfgang Hottgenroth <woho@hottis.de>"
 LABEL ImageName=""
@@ -7,27 +7,15 @@ LABEL ImageName=""
 ENV LOCALMAILNAME=""
 # smarthost to send mail to
 ENV SMARTHOST=""
-# recipient addresses for root aliases, separate multiple addresses by space
-ENV ROOT=""
 # ip addresses or networks to allow for relaying, separate multiple ones by semicolon
 ENV RELAYNETS=""
 
-RUN \
-  apt update && \
-  apt upgrade -y --autoremove && \
-  apt install -y exim4-daemon-light ca-certificates curl && \ 
-  rm -rf /var/lib/apt/lists/*
+RUN apk add --no-cache exim bash
 
-COPY update-exim4.conf.tmpl /etc/exim4/
-COPY aliases.tmpl /etc/exim4/
-COPY adjust-config.sh /etc/exim4/
-COPY start.sh /etc/exim4/
-
-WORKDIR /etc/exim4
+WORKDIR /etc/exim
 
 EXPOSE 25
 
-CMD [ "./start.sh" ]