diff --git a/README.virtual-do-not-reply b/README.virtual-do-not-reply
new file mode 100644
index 0000000..97293cb
--- /dev/null
+++ b/README.virtual-do-not-reply
@@ -0,0 +1,159 @@
+# ====================
+# Forward E-Mails to 'do-not-reply@..' address to (file) /dev/null
+# ====================
+
+# ---
+# Example for this readme:
+#
+# Create a forwarding to /dev/null for the address no-reply@cloud-01.oopen.de
+# ---
+
+DOMAIN=""cloud-01.oopen.de
+E_MAIL="no-reply@cloud-01.oopen.de"
+
+# see also:
+#     https://www.postfix.org/VIRTUAL_README.html
+#
+#     https://think.unblog.ch/weiterleiten-von-postfix-alias-an-dev-null/
+#     https://think.unblog.ch/en/forward-postfix-alias-to-dev-null/
+#
+#     https://www.serverwatch.com/guides/forwarding-a-postfix-virtual-alias-to-dev-null/
+
+
+# Notice:
+#     the usual solution is to forward to (file) /dev/null. In a local-only setup you could do 
+#     that in /etc/aliases.
+#
+#     However, if your're using Postfix virtual domains, it gets a little more complicated. With 
+#     virtual domains/users, you can't forward mail to a file (like /dev/null). 
+
+
+# ---
+# 1. Set up an alias user 'do-not-reply'that forwards incoming e-mails to /dev/null.
+# ---
+
+# Add to file '/etc/aliases' a line like:
+#     do-not-reply: /dev/null
+
+if ! $(grep -q -E "^\s*do-not-reply:" /etc/aliases 2>/devnull) ; then
+   cat <<EOF >> /etc/aliases
+
+do-not-reply: /dev/null
+EOF
+fi
+
+# Renew alias database:
+#
+newaliases
+
+
+# ---
+# 2. Set up the domain (domain part of not-reply address)
+# ---
+
+# Create file '/etc/postfix/virtual_alias_domains' and add your domain '@cloud-01.oopen.de'
+#
+#  ${DOMAIN}         OK
+#
+if [[ ! -f "/etc/postfix/virtual_alias_domains" ]] ; then
+
+   cat <<EOF >> /etc/postfix/virtual_alias_domains
+# - File: /etc/postfix/virtual_alias_domains
+# -
+# - Note:
+# -  a mapping file always has two columns. In such a 'one-dimensional' mapping (list of domains) 
+# -  Postfix does not care about your second column. It does not even have to be 'OK', it can be
+# -  anything.
+# -
+# - Example:
+# -      <domain>            OK
+
+${DOMAIN}    OK
+EOF
+else
+   if ! $(grep -q -E "^\s*${DOMAIN}" /etc/postfix/virtual_alias_domains 2> /dev/null) ; then
+      cat <<EOF >> /etc/postfix/virtual_alias_domains
+
+${DOMAIN}    OK
+EOF
+   fi
+fi
+
+
+# Create Postfix lookup table (database file) from '/etc/postfix/virtual_alias_domains'
+#
+postmap btree:/etc/postfix/virtual_alias_domains
+
+
+# Add virtual_alias_domains to Postfix main Configuration
+#
+#  ...
+#  virtual_alias_domains =
+#     btree:/etc/postfix/virtual_alias_domains
+#  ...
+#
+if ! $(grep -q -E "^\s*virtual_alias_domains\s*=\s*btree:/etc/postfix/virtual_alias_domains" /etc/postfix/main.cf) \
+      && ! $(grep -q -E "^\s*btree:/etc/postfix/virtual_alias_domains" /etc/postfix/main.cf); then
+   perl -i -n -p -e "s#^(\s*virtual_alias_domains\s*=.*)#\1\n   btree:/etc/postfix/virtual_alias_domains#" /etc/postfix/main.cf
+fi
+
+
+
+# ---
+# 3. Set up adress mapping
+# ---
+
+# - Create file '/etc/postfix/virtual_alias_maps' and add your address mapping
+# -
+# -      ${E_MAIL}         do-not-reply
+# -
+if [[ ! -f "/etc/postfix/virtual_alias_maps" ]] ; then
+
+   cat <<EOF >> /etc/postfix/virtual_alias_maps
+# - File: /etc/postfix/virtual_alias_maps
+# -
+# - Redirect mail for one address to one or more addresses.
+# -
+# - Example:
+# -   # incomming address 'no-reply@cloud-01.oopen.de' to local 'do-not-reply' address
+#     no-reply@cloud-01.oopen.de    do-not-reply
+#
+
+${E_MAIL}      do-not-reply
+EOF
+else
+   if ! $(grep -q -E "^\s*${E_MAIL}" /etc/postfix/virtual_alias_maps 2> /dev/null) ; then
+      cat <<EOF >> /etc/postfix/virtual_alias_maps
+
+${E_MAIL}      do-not-reply
+EOF
+   fi
+fi
+
+
+# Create Postfix lookup table (database file) from '/etc/postfix/virtual_alias_maps'
+#
+postmap btree:/etc/postfix/virtual_alias_maps
+
+
+
+
+# Add virtual_alias_maps to Postfix main Configuration
+#
+#  ...
+#  virtual_alias_maps =
+#     btree:/etc/postfix/virtual_alias_maps
+#  ...
+#
+if ! $(grep -q -E "^\s*virtual_alias_maps\s*=\s*btree:/etc/postfix/virtual_alias_maps" /etc/postfix/main.cf) \
+      && ! $(grep -q -E "^\s*btree:/etc/postfix/virtual_alias_maps" /etc/postfix/main.cf); then
+   perl -i -n -p -e "s#^(\s*virtual_alias_maps\s*=.*)#\1\n   btree:/etc/postfix/virtual_alias_maps#" /etc/postfix/main.cf
+fi
+
+
+# ---
+# 4. Reload Postfix
+# ---
+
+systemctl reload postfix
+