diff --git a/Dockerfile b/Dockerfile
index 267c86d4..f2c83054 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -32,9 +32,11 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get update -q --fix-missing && \
     opendmarc \
     p7zip \
     postfix \
+    postfix-ldap \
     pyzor \
     razor \
     rsyslog \
+    sasl2-bin \
     spamassassin \
     unzip \
     && \
diff --git a/Makefile b/Makefile
index 18545b96..ac3abe43 100644
--- a/Makefile
+++ b/Makefile
@@ -76,6 +76,31 @@ run:
 		-e SSL_CERT_PATH=/tmp/docker-mailserver/letsencrypt/mail.my-domain.com/fullchain.pem \
 		-e SSL_KEY_PATH=/tmp/docker-mailserver/letsencrypt/mail.my-domain.com/privkey.pem \
 		-h mail.my-domain.com -t $(NAME)
+	docker run -d --name mail_enable_ldap \
+		-v "`pwd`/test/config":/tmp/docker-mailserver \
+		-v "`pwd`/test":/tmp/docker-mailserver-test \
+		-e LDAP=1 \
+		-e SMTP_ONLY=1 \
+		-h mail.my-domain.com -t $(NAME)
+	docker run -d --name mail_enable_sasl_ldap \
+		-v "`pwd`/test/config":/tmp/docker-mailserver \
+		-v "`pwd`/test":/tmp/docker-mailserver-test \
+		-e SASLAUTHD=1 \
+		-e "SASL_LDAP_SERVER=192.168.0.100" \
+		-e SASL_LDAP_PROTO= \
+		-e "SASL_LDAP_BIND_DN=cn=Administrator,cn=Users,dc=my,dc=domain" \
+		-e SASL_LDAP_PASSWORD=test \
+		-e "SASL_LDAP_SEARCH_BASE=dc=my,dc=domain" \
+		-e "SASL_LDAP_FILTER=(&(sAMAccountName=%U)(objectClass=person))" \
+		-e SASL_MECHANISMS=ldap \
+		-e SMTP_ONLY=1 \
+		-h mail.my-domain.com -t $(NAME)
+	docker run -d --name mail_enable_kopano \
+		-v "`pwd`/test/config":/tmp/docker-mailserver \
+		-v "`pwd`/test":/tmp/docker-mailserver-test \
+		-e KOPANO=1 \
+		-e SMTP_ONLY=1 \
+		-h mail.my-domain.com -t $(NAME)
 	# Wait for containers to fully start
 	sleep 20
 
diff --git a/README.md b/README.md
index 71ae5f8e..ca9cee00 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,10 @@ Includes:
 - opendmarc
 - fail2ban
 - fetchmail
+- saslauthd
+- saslauthd ldap support
+- postfix ldap support
+- kopano support
 - basic [sieve support](https://github.com/tomav/docker-mailserver/wiki/Configure-Sieve-filters) using dovecot
 - [LetsEncrypt](https://letsencrypt.org/) and self-signed certificates
 - [integration tests](https://travis-ci.org/tomav/docker-mailserver)
@@ -147,7 +151,6 @@ Otherwise, `iptables` won't be able to ban IPs.
   - custom => Enables custom certificates
   - manual => Let's you manually specify locations of your SSL certificates for non-standard cases
   - self-signed => Enables self-signed certificates
-
 Please read [the SSL page in the wiki](https://github.com/tomav/docker-mailserver/wiki/Configure-SSL) for more information.
 
 ##### PERMIT_DOCKER
@@ -157,6 +160,68 @@ Set different options for mynetworks option (can be overwrite in postfix-main.cf
   - host => Add docker host (ipv4 only)
   - network => Add all docker containers (ipv4 only)
 
+##### SASL_MECHANISMS
+  - empty => pam
+  - ldap => authenticate against ldap server
+  - shadow => authenticate against local user db
+  - mysql => authenticate against mysql db
+  - rimap => authenticate against imap server
+  - NOTE: can be a list of mechanisms like pam ldap shadow
+
+##### SASL_MECH_OPTIONS
+  - empty => None
+  - e.g. with sasl_mechanism rimap you need to specify the ip-address/servername of the imap server  ==> xxx.xxx.xxx.xxx
+
+##### SASL_LDAP_SERVER
+  - empty => localhost
+
+##### SASL_LDAP_PROTO
+  - empty => ldap://
+  - 1 => ldaps://
+
+##### SASL_LDAP_BIND_DN
+  - empty => anonymous bind
+  - specify an object with priviliges to search the directory tree
+  - e.g. active directory: SASL_BIND_DN=cn=Administrator,cn=Users,dc=mydomain,dc=net
+  - e.g. openldap: SASL_BIND_DN=cn=admin,dc=mydomain,dc=net
+
+##### SASL_LDAP_PASSWORD
+  - empty => anonymous bind
+
+##### SASL_LDAP_SEARCH_BASE
+  - empty => Reverting to SASL_MECHANISM pam
+  - specify the search base
+
+##### SASL_LDAP_FILTER
+  - empty => default filter (uid=%u)
+  - e.g. for active directory: (&(sAMAccountName=%U)(objectClass=person))
+  - e.g. for openldap: (&(uid=%U)(objectClass=person))
+
+##### LDAP
+  - **empty** => LDAP support disabled
+  - 1 => set virtual_mailbox_maps = ldap:/etc/postfix/ldap-users.cf and virtual_alias_maps = ldap:/etc//postfix/ldap-aliases.cf
+  - $SMTP_ONLY must be set to 1
+
+##### LDAP_SERVER_HOST
+  - => Specify the dns-name/ip-address where the ldap-server
+  - NOTE: If you going to use the mailserver in combination with docker-compose you can set the service name here
+
+##### LDAP_SEARCH_BASE
+  - => e.g. LDAP_SEARCH_BASE=dc=mydomain,dc=loc
+
+##### LDAP_BIND_DN
+  - => take a look at examples of SASL_LDAP_BIND_DN
+
+##### LDAP_BIND_PW
+  - => Specify the password to bind against ldap
+
+##### KOPANO
+  - **empty** => LDAP support disabled disabled
+  - 1 => set virtual_transport = ltmp:${KOPANO_DAGENT}:2003
+
+##### KOPANO_DAGENT
+  - => Specify the dns-name/ip-address where the kopano-dagent can be reached
+
 ##### VIRUSMAILS_DELETE_DELAY
 
 Set how many days a virusmail will stay on the server before being deleted
diff --git a/config/postfix-ldap-aliases.cf b/config/postfix-ldap-aliases.cf
new file mode 100644
index 00000000..a0389705
--- /dev/null
+++ b/config/postfix-ldap-aliases.cf
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Users,dc=example,dc=com
+version = 3
+scope = sub
+query_filter = (&(objectClass=posixAccount)(kopanoAliases=%s))
+result_attribute = mail
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/config/postfix-ldap-aliases.cf.activedirectory b/config/postfix-ldap-aliases.cf.activedirectory
new file mode 100644
index 00000000..7fb66cf8
--- /dev/null
+++ b/config/postfix-ldap-aliases.cf.activedirectory
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=Users,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+scope = sub
+query_filter = (&(objectClass=user)(otherMailbox=%s))
+result_attribute = mail
+bind = yes
diff --git a/config/postfix-ldap-aliases.cf.openldap b/config/postfix-ldap-aliases.cf.openldap
new file mode 100644
index 00000000..a0389705
--- /dev/null
+++ b/config/postfix-ldap-aliases.cf.openldap
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Users,dc=example,dc=com
+version = 3
+scope = sub
+query_filter = (&(objectClass=posixAccount)(kopanoAliases=%s))
+result_attribute = mail
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/config/postfix-ldap-groups.cf b/config/postfix-ldap-groups.cf
new file mode 100644
index 00000000..f91fcc4c
--- /dev/null
+++ b/config/postfix-ldap-groups.cf
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Groups,dc=exampple,dc=com
+version = 3
+query_filter = (&(objectclass=kopano-group)(mail=%s))
+leaf_result_attribute = mail
+special_result_attribute = member
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/config/postfix-ldap-groups.cf.activedirectory b/config/postfix-ldap-groups.cf.activedirectory
new file mode 100644
index 00000000..c6ede4e7
--- /dev/null
+++ b/config/postfix-ldap-groups.cf.activedirectory
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=groups,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+query_filter = (&(objectclass=group)(mail=%s))
+leaf_result_attribute = mail
+special_result_attribute = member
+bind = yes
diff --git a/config/postfix-ldap-groups.cf.openldap b/config/postfix-ldap-groups.cf.openldap
new file mode 100644
index 00000000..f91fcc4c
--- /dev/null
+++ b/config/postfix-ldap-groups.cf.openldap
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Groups,dc=exampple,dc=com
+version = 3
+query_filter = (&(objectclass=kopano-group)(mail=%s))
+leaf_result_attribute = mail
+special_result_attribute = member
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/config/postfix-ldap-users.cf b/config/postfix-ldap-users.cf
new file mode 100644
index 00000000..b817a580
--- /dev/null
+++ b/config/postfix-ldap-users.cf
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Users,dc=example,dc=com
+version = 3
+scope = sub
+query_filter = (&(objectClass=posixAccount)(mail=%s))
+result_attribute = mail
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/config/postfix-ldap-users.cf.activedirectory b/config/postfix-ldap-users.cf.activedirectory
new file mode 100644
index 00000000..af4280e4
--- /dev/null
+++ b/config/postfix-ldap-users.cf.activedirectory
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=Users,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+scope = sub
+query_filter = (&(objectClass=user)(mail=%s))
+result_attribute = mail
+bind = yes
diff --git a/config/postfix-ldap-users.cf.openldap b/config/postfix-ldap-users.cf.openldap
new file mode 100644
index 00000000..b817a580
--- /dev/null
+++ b/config/postfix-ldap-users.cf.openldap
@@ -0,0 +1,9 @@
+server_host = localhost
+search_base = ou=Users,dc=example,dc=com
+version = 3
+scope = sub
+query_filter = (&(objectClass=posixAccount)(mail=%s))
+result_attribute = mail
+bind_dn =
+bind_pw =
+bind = yes
diff --git a/target/start-mailserver.sh b/target/start-mailserver.sh
index cb3a9b43..9f5dd7e0 100644
--- a/target/start-mailserver.sh
+++ b/target/start-mailserver.sh
@@ -69,12 +69,14 @@ if [ -f /tmp/docker-mailserver/postfix-accounts.cf ]; then
     fi
     # Copy user provided sieve file, if present
     test -e /tmp/docker-mailserver/${login}.dovecot.sieve && cp /tmp/docker-mailserver/${login}.dovecot.sieve /var/mail/${domain}/${user}/.dovecot.sieve
-    echo ${domain} >> /tmp/vhost.tmp
   done < /tmp/docker-mailserver/postfix-accounts.cf
 else
   echo "==> Warning: 'config/docker-mailserver/postfix-accounts.cf' is not provided. No mail account created."
 fi
 
+# Create default vhost file
+echo ${domain} >> /tmp/vhost.tmp
+
 #
 # Aliases
 #
@@ -258,6 +260,96 @@ case $PERMIT_DOCKER in
 
 esac
 
+#
+# Ldap
+#
+for i in 'users' 'groups' 'aliases'; do
+    fpath="/tmp/docker-mailserver/postfix-ldap-${i}.cf"
+    if [ -f $fpath ]; then
+        cp ${fpath} /etc/postfix/ldap-${i}.cf
+        sed -i -e 's|^server_host.*|server_host = '${LDAP_SERVER_HOST}'|g' \
+               -e 's|^search_base.*|search_base = '${LDAP_SEARCH_BASE}'|g' \
+               -e 's|^bind_dn.*|bind_dn = '${LDAP_BIND_DN}'|g' \
+               -e 's|^bind_pw.*|bind_pw = '${LDAP_BIND_PW}'|g' \
+               /etc/postfix/ldap-${i}.cf
+    else
+        echo "${fpath} not found"
+        echo "==> Warning: 'config/postfix-ldap-$i.cf' is not provided."
+    fi
+done
+
+if [[ $LDAP == 1 ]] && [[ $SMTP_ONLY == 1 ]];then
+
+    echo "Configuring LDAP"
+    [ -f /etc/postfix/ldap-users.cf ] && \
+        postconf -e "virtual_mailbox_maps = ldap:/etc/postfix/ldap-users.cf" || \
+        echo '==> Warning: /etc/postfix/ldap-user.cf not found'
+
+    [ -f /etc/postfix/ldap-aliases.cf ] && \
+    postconf -e "virtual_alias_maps = ldap:/etc/postfix/ldap-aliases.cf, ldap:/etc/postfix/ldap-groups.cf" || \
+        echo '==> Warning: /etc/postfix/ldap-aliases.cf not found'
+
+    [ ! -f /etc/postfix/sasl/smtpd.conf ] && cat > /etc/postfix/sasl/smtpd.conf << EOF
+pwcheck_method: saslauthd
+mech_list: plain login
+EOF
+fi
+
+#
+# Saslauthd
+#
+if [ ${SASLAUTHD} == 1 ];then 
+    echo "Configuring Cyrus SASL"
+    # checking env vars and setting defaults
+    [ -z $SASL_MECHANISMS ] && SASL_MECHANISMS=pam
+    [ -z $SASL_LDAP_SEARCH_BASE ] && SASL_MECHANISMS=pam
+    [ -z $SASL_LDAP_SERVER ] && SASL_LDAP_SERVER=localhost
+    [ -z $SASL_LDAP_FILTER ] && SASL_LDAP_FILTER='(uid=%u)'
+    ([ $SASL_LDAP_PROTO == 0 ] || [ -z $SASL_LDAP_PROTO ]) && SASL_LDAP_PROTO='ldap://' || SASL_LDAP_PROTO='ldaps://'
+
+    if [ ! -f /etc/saslauthd.conf ];then
+        echo "Creating /etc/saslauthd.conf"
+        cat > /etc/saslauthd.conf << EOF
+ldap_servers: ${SASL_LDAP_PROTO}${SASL_LDAP_SERVER}
+
+ldap_auth_method: bind
+ldap_bind_dn: ${SASL_LDAP_BIND_DN}
+ldap_password: ${SASL_LDAP_PASSWORD}
+
+ldap_search_base: ${SASL_LDAP_SEARCH_BASE}
+ldap_filter: ${SASL_LDAP_FILTER}
+
+ldap_referrals: yes
+log_level: 10
+EOF
+
+    fi
+
+    sed -i -e "/^[^#].*smtpd_sasl_type.*/s/^/#/g" \
+           -e "/^[^#].*smtpd_sasl_path.*/s/^/#/g" \
+            /etc/postfix/master.cf
+
+    sed -i -e "s|^START=.*|START=yes|g" \
+           -e "s|^MECHANISMS=.*|MECHANISMS="\"$SASL_MECHANISMS\""|g" \
+           -e "s|^MECH_OPTIONS=.*|MECH_OPTIONS="\"$SASL_MECH_OPTIONS\""|g" \
+        /etc/default/saslauthd
+    sed -i -e "/smtpd_sasl_path =.*/d" \
+           -e "/smtpd_sasl_type =.*/d" \
+           -e "/dovecot_destination_recipient_limit =.*/d" \
+           /etc/postfix/main.cf
+    gpasswd -a postfix sasl
+fi
+
+#
+# Kopano
+#
+if [ $KOPANO == 1 ];then
+    echo 'Configuring Kopano' 
+    [ ! -z ${KOPANO_DAGENT} ] && \
+    postconf -e "virtual_transport = lmtp:${KOPANO_DAGENT}:2003" || \
+    echo '$KOPANO_DAGENT not set. Skipping ...'
+fi
+    
 #
 # Override Postfix configuration
 #
@@ -378,57 +470,63 @@ if [ "$ENABLE_MANAGESIEVE" = 1 ]; then
   echo "Sieve management enabled"
   mv /etc/dovecot/protocols.d/managesieved.protocol.disab /etc/dovecot/protocols.d/managesieved.protocol
 fi
-
 if [ "$SMTP_ONLY" != 1 ]; then
-  # Here we are starting sasl and imap, not pop3 because it's disabled by default
-  echo " * Starting dovecot services"
-  /usr/sbin/dovecot -c /etc/dovecot/dovecot.conf
-fi
+    # Here we are starting sasl and imap, not pop3 because it's disabled by default
+    echo " * Starting dovecot services"
+    /usr/sbin/dovecot -c /etc/dovecot/dovecot.conf
 
-if [ "$ENABLE_POP3" = 1 -a "$SMTP_ONLY" != 1 ]; then
-  echo "Starting POP3 services"
-  mv /etc/dovecot/protocols.d/pop3d.protocol.disab /etc/dovecot/protocols.d/pop3d.protocol
-  /usr/sbin/dovecot reload
-fi
+    if [ "$ENABLE_POP3" = 1 ]; then
+        echo "Starting POP3 services"
+        mv /etc/dovecot/protocols.d/pop3d.protocol.disab /etc/dovecot/protocols.d/pop3d.protocol
+        /usr/sbin/dovecot reload
+    fi
 
-if [ -f /tmp/docker-mailserver/dovecot.cf ]; then
-  echo 'Adding file "dovecot.cf" to the Dovecot configuration'
-  cp /tmp/docker-mailserver/dovecot.cf /etc/dovecot/local.conf
-  /usr/sbin/dovecot reload
+    if [ -f /tmp/docker-mailserver/dovecot.cf ]; then
+        echo 'Adding file "dovecot.cf" to the Dovecot configuration'
+        cp /tmp/docker-mailserver/dovecot.cf /etc/dovecot/local.conf
+        /usr/sbin/dovecot reload
+    fi
 fi
 
 # Enable fetchmail daemon
 if [ "$ENABLE_FETCHMAIL" = 1 ]; then
-  /usr/local/bin/setup-fetchmail
-  echo "Fetchmail enabled"
-  /etc/init.d/fetchmail start
+    /usr/local/bin/setup-fetchmail
+    echo "Fetchmail enabled"
+    /etc/init.d/fetchmail start
 fi
 
 # Start services related to SMTP
 if ! [ "$DISABLE_CLAMAV" = 1 ]; then
-  /etc/init.d/clamav-daemon start
+    /etc/init.d/clamav-daemon start
 fi
 
 # Copy user provided configuration files if provided
 if [ -f /tmp/docker-mailserver/amavis.cf ]; then
-  cp /tmp/docker-mailserver/amavis.cf /etc/amavis/conf.d/50-user
+    cp /tmp/docker-mailserver/amavis.cf /etc/amavis/conf.d/50-user
 fi
 
 if ! [ "$DISABLE_AMAVIS" = 1 ]; then
-  /etc/init.d/amavis start
+    /etc/init.d/amavis start
 fi
+
+if [[ $SMTP_ONLY == 1 ]] && [[ $LDAP == 1 ]]; then
+    /etc/init.d/saslauthd start
+fi
+
 /etc/init.d/opendkim start
 /etc/init.d/opendmarc start
 /etc/init.d/postfix start
 
 if [ "$ENABLE_FAIL2BAN" = 1 ]; then
-  echo "Starting fail2ban service"
-  touch /var/log/auth.log
-  /etc/init.d/fail2ban start
+    echo "Starting fail2ban service"
+    touch /var/log/auth.log
+    /etc/init.d/fail2ban start
 fi
 
-echo "Listing users"
-/usr/sbin/dovecot user '*'
+if [ ! "$SMTP_ONLY" == 1 ];then
+    echo "Listing users"
+    /usr/sbin/dovecot user '*'
+fi
 
 echo "Starting..."
 tail -f /var/log/mail/mail.log
diff --git a/test/config/postfix-ldap-aliases.cf b/test/config/postfix-ldap-aliases.cf
new file mode 100644
index 00000000..7fb66cf8
--- /dev/null
+++ b/test/config/postfix-ldap-aliases.cf
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=Users,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+scope = sub
+query_filter = (&(objectClass=user)(otherMailbox=%s))
+result_attribute = mail
+bind = yes
diff --git a/test/config/postfix-ldap-groups.cf b/test/config/postfix-ldap-groups.cf
new file mode 100644
index 00000000..c6ede4e7
--- /dev/null
+++ b/test/config/postfix-ldap-groups.cf
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=groups,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+query_filter = (&(objectclass=group)(mail=%s))
+leaf_result_attribute = mail
+special_result_attribute = member
+bind = yes
diff --git a/test/config/postfix-ldap-users.cf b/test/config/postfix-ldap-users.cf
new file mode 100644
index 00000000..af4280e4
--- /dev/null
+++ b/test/config/postfix-ldap-users.cf
@@ -0,0 +1,10 @@
+server_host = 192.168.0.100
+search_base = ou=Users,dc=example,dc=local
+version = 3
+bind = yes
+bind_dn = cn=kopano,ou=Users,dc=example,dc=local
+bind_pw = secret
+scope = sub
+query_filter = (&(objectClass=user)(mail=%s))
+result_attribute = mail
+bind = yes