diff --git a/data/misc/mailcow-setup-relayhost.sh b/data/misc/mailcow-setup-relayhost.sh
new file mode 100755
index 00000000..486435a8
--- /dev/null
+++ b/data/misc/mailcow-setup-relayhost.sh
@@ -0,0 +1,91 @@
+#!/bin/bash
+
+# Postfix smtp_tls_security_level should be set to "may" to try an
+# encrypted connection.
+
+if [ "$EUID" -ne 0 ]
+	then echo "Please run as root"
+	exit 1
+fi
+
+# Find script directory and move to base directory of mailcow-dockerized
+# so docker-compose is executed from the right location
+DIR=$(echo $( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd ) | sed 's/data\/misc.*//')
+cd $DIR
+
+if [[ ${1} == "reset" ]]; then
+	# Reset modified values to their defaults
+	sed -i "s/^relayhost\ \=.*/relayhost\ \=/" data/conf/postfix/main.cf
+	sed -i "s/^smtp\_sasl\_password\_maps.*/smtp\_sasl\_password\_maps\ \=/" data/conf/postfix/main.cf
+	sed -i "s/^smtp\_sasl\_security\_options.*/smtp\_sasl\_security\_options\ \=\ noplaintext\,\ noanonymous/" data/conf/postfix/main.cf
+	sed -i "s/^smtp\_sasl\_auth\_enable.*/smtp\_sasl\_auth\_enable\ \=\ no/" data/conf/postfix/main.cf
+	# Also delete the plaintext password file
+	rm -f data/conf/postfix/smarthost_passwd*
+	docker-compose exec postfix-mailcow postfix reload
+	# Exit last exit code
+	exit $?
+elif [[ ${1} == "restore-string" ]]; then
+	# Set parameter value of smtp_sasl_password_maps
+	SMTPSASLPWDMAP="data/conf/postfix/smarthost_passwd"
+	# Get parameter value of relayhost
+	RELAYHOSTCFG=$(grep "relayhost\ =" data/conf/postfix/main.cf | awk '{print $3}')
+	# Exit if empty/unset
+	[[ -z ${RELAYHOSTCFG} ]] && exit 0
+	# Replace ':' by ' ' (white space)
+	RELAYHOSTCFG=${RELAYHOSTCFG//\:/ }
+	# Replace '[' by '' (empty)
+	RELAYHOSTCFG=${RELAYHOSTCFG//\[/}
+	# Replace ']' by '' (empty) and create array of result
+	RELAYHOSTCFGARR=(${RELAYHOSTCFG//\]/})
+	# Get 'username:password' from SASL password maps
+	# Grep relayhost without port and '[', ']' or ':' from SASL password map file without map type (e.g. 'hash:')
+	USRPWD=$(grep ${RELAYHOSTCFGARR[0]} $SMTPSASLPWDMAP | awk {'print $2'})
+	# Replace ':' by ' ' and create array of result
+	USRPWDARR=(${USRPWD//:/ })
+	# Echo script name, all values in RELAYHOSTCFGARR, first and second value in USRPWDARR
+	# Why?
+	# Host and port are required, so we can print the whole array RELAYHOSTCFGARR.
+	# Password might be empty, so we print them separately.
+	echo ${0} ${RELAYHOSTCFGARR[@]} \'${USRPWDARR[0]}\' \'${USRPWDARR[1]}\'
+	exit 0
+elif [[ -z ${1} ]] || [[ -z ${2} ]]; then
+	# Exit with code 1 if host and port are missing
+	echo "Usage: ${0} relayhost port (username) (password)"
+	echo "Username and password are optional parameters."
+	exit 1
+else
+	# Try a simple connection to host:port but don't recieve any data
+	# Abort after 3 seconds
+	if ! nc -z -v -w3 ${1} ${2} 2>/dev/null; then
+		echo "Connection to relayhost ${1} failed, aborting..."
+		exit 1
+	fi
+	# Use exact hostname as relayhost, don't lookup the MX record of relayhost
+	sed -i "s/relayhost\ \=.*/relayhost\ \=\ \[${1}\]\:${2}/" data/conf/postfix/main.cf
+	if grep -q "smtp_sasl_password_maps" data/conf/postfix/main.cf
+	then
+		sed -i "s/^smtp\_sasl\_password\_maps.*/smtp\_sasl\_password\_maps\ \=\ hash\:\/opt\/postfix\/conf\/smarthost\_passwd/" data/conf/postfix/main.cf
+	else
+		echo "smtp_sasl_password_maps = hash:/opt/postfix/conf/smarthost_passwd" >>  data/conf/postfix/main.cf
+	fi
+	if grep -q "smtp_sasl_auth_enable" data/conf/postfix/main.cf
+	then
+		sed -i "s/^smtp\_sasl\_auth\_enable.*/smtp\_sasl\_auth\_enable\ \=\ yes/" data/conf/postfix/main.cf
+	else
+		echo "smtp_sasl_auth_enable = yes" >>  data/conf/postfix/main.cf
+	fi
+	if grep -q "smtp_sasl_security_options" data/conf/postfix/main.cf
+	then
+		sed -i "s/^smtp\_sasl\_security\_options.*/smtp\_sasl\_security\_options\ \=/" data/conf/postfix/main.cf
+	else
+		echo "smtp_sasl_security_options =" >>  data/conf/postfix/main.cf
+	fi
+	if [[ ! -z ${3} ]]; then
+		echo ${1} ${3}:${4} > data/conf/postfix/smarthost_passwd
+		docker-compose exec postfix-mailcow postmap /opt/postfix/conf/smarthost_passwd
+	fi
+	docker-compose exec postfix-mailcow chown root:postfix /opt/postfix/conf/smarthost_passwd /opt/postfix/conf/smarthost_passwd.db
+	docker-compose exec postfix-mailcow chmod 660 /opt/postfix/conf/smarthost_passwd /opt/postfix/conf/smarthost_passwd.db
+	docker-compose exec postfix-mailcow postfix reload
+	exit $?
+fi