Add test mgr setup

mail.Dockerfile

@@ -0,0 +1,23 @@
+FROM debian:buster
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive \
+    apt-get install -y --no-install-recommends \
+    ca-certificates \
+    curl \
+    dovecot-imapd \
+    dumb-init \
+    mutt \
+    psmisc \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+EXPOSE 143
+
+RUN adduser --uid 1000 --gecos "catchall mailbox" --disabled-password catchall
+
+VOLUME /home/catchall/Maildir
+
+COPY docker/run-dovecot /usr/local/bin/run-dovecot
+
+CMD ["dumb-init", "/usr/local/bin/run-dovecot"]