diff --git a/Dockerfile b/Dockerfile
index f6bf100..2a52243 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,8 +3,12 @@ MAINTAINER Bojan Cekrlic
 
 # You can set this variables when running the image to override the host name or
 # foward the messages to another server
-#ENV	HOSTNAME
-#ENV	RELAYHOST
+# ENV	HOSTNAME
+# Hostname that will be used in the outgoing mail
+# ENV	RELAYHOST
+# The relay host for this server
+# ENV	ALLOWED_SENDER_DOMAINS
+# Limit the list of sending domains to this list only
 
 RUN	true && \
 	apk add --no-cache --update postfix ca-certificates supervisor rsyslog bash && \
@@ -15,9 +19,10 @@ COPY	rsyslog.conf /etc/rsyslog.conf
 COPY	postfix.sh /postfix.sh
 RUN	chmod +x /postfix.sh
 
-VOLUME	[ "/var/spool/postfix" ]
+VOLUME	[ "/var/spool/postfix", "/etc/postfix" ]
 
 USER	root
 WORKDIR	/tmp
-ENTRYPOINT ["/usr/bin/supervisord", "-c", "/etc/supervisord.conf"]
 
+EXPOSE 587
+ENTRYPOINT ["/usr/bin/supervisord", "-c", "/etc/supervisord.conf"]
diff --git a/postfix.sh b/postfix.sh
index 786b6ba..b1b7a7f 100644
--- a/postfix.sh
+++ b/postfix.sh
@@ -1,15 +1,63 @@
 #!/bin/bash
 
+# Disable local mail delivery
+postconf -e mydestination=
+# Don't relay for any domains
+postconf -e relay_domains=
+
+# Reject invalid HELOs
+postconf -e smtpd_delay_reject=yes
+postconf -e smtpd_helo_required=yes
+postconf -e "smtpd_helo_restrictions=permit_mynetworks,reject_invalid_helo_hostname,permit"
+
+# Set up host name
 if [[ ! -z "$HOSTNAME" ]]; then
 	postconf -e myhostname=$HOSTNAME
 else
 	postconf -# myhostname
 fi
 
+# Set up a relay host, if needed
 if [[ ! -z "$RELAYHOST" ]]; then
 	postconf -e relayhost=$RELAYHOST
 else
 	postconf -# relayhost
 fi
 
+# Set up my networks to list only networks in the local loopback range
+#network_table=/etc/postfix/network_table
+#touch $network_table
+#echo "127.0.0.0/8    any_value" >  $network_table
+#echo "10.0.0.0/8     any_value" >> $network_table
+#echo "172.16.0.0/12  any_value" >> $network_table
+#echo "192.168.0.0/16 any_value" >> $network_table
+## Ignore IPv6 for now
+##echo "fd00::/8" >> $network_table
+#postmap $network_table
+#postconf -e mynetworks=hash:$network_table
+postconf -e "mynetworks=127.0.0.0/8,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16"
+
+# Split with space
+if [[ ! -z "$ALLOWED_SENDER_DOMAINS" ]]; then
+	echo "Setting up allowed SENDER domains:"
+	allowed_senders=/etc/postfix/allowed_senders
+	rm -f $allowed_senders $allowed_senders.db > /dev/null
+	touch $allowed_senders
+	for i in "$ALLOWED_SENDER_DOMAINS"; do
+		echo -e "\t$i"
+		echo -e "$i\tOK" >> $allowed_senders
+	done
+	postmap $allowed_senders
+
+	postconf -e "smtpd_restriction_classes=allowed_domains_only"
+	postconf -e "allowed_domains_only=permit_mynetworks, reject_non_fqdn_sender reject"
+	postconf -e "smtpd_recipient_restrictions=reject_non_fqdn_recipient, reject_unknown_recipient_domain, reject_unverified_recipient, check_sender_access hash:$allowed_senders, reject"
+else
+	postconf -# "smtpd_restriction_classes"
+	postconf -e "smtpd_recipient_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,reject_unverified_recipient"
+fi
+
+# Use 587 (submission)
+sed -i -r -e 's/^#submission/submission/' /etc/postfix/master.cf
+
 /usr/sbin/postfix -c /etc/postfix start
diff --git a/rsyslog.conf b/rsyslog.conf
index 44ed1ad..b0a8716 100644
--- a/rsyslog.conf
+++ b/rsyslog.conf
@@ -10,5 +10,4 @@ $Umask 0022
 
 #*.info							/dev/stdout
 #mail.*							/dev/stdout
-mail.info	/dev/stdout
-
+mail.info	          /dev/stdout
diff --git a/supervisord.conf b/supervisord.conf
index e9786c2..765c909 100644
--- a/supervisord.conf
+++ b/supervisord.conf
@@ -15,8 +15,9 @@ stdout_logfile_maxbytes = 0
 stderr_logfile_maxbytes = 0
 
 [program:postfix]
-process_name	= master
-directory	= /etc/postfix
-command		= /postfix.sh
-startsecs	= 0
-autorestart	= false
+process_name    = master
+autostart       = true
+autorestart     = false
+directory       = /etc/postfix
+command         = /postfix.sh
+startsecs       = 0