diff --git a/Dockerfile b/Dockerfile
index acca4f2..7426147 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,3 +7,7 @@ COPY conf /etc/postfix
 COPY rsyslog.conf /etc/rsyslog.conf
 
 COPY monit-service.conf /opt/monit/etc/conf.d 
+
+VOLUME ["/var/spool/postfix"]
+
+EXPOSE 25