The real_domains (e.g., vserver hostnames) are mostly not listed in the
DNS, so we replace that with our public DNS name.
--- /dev/null
+################################
+# If any of the real_domains is left in the envelope, rewrite it to our
+# external hostname, since most real_domains are not listed in DNS.
+# Don't rewrite the From address, so we can still see where a message
+# comes from.
+#################################
+
+*@+real_domains $1@EXTERNAL_HOSTNAME E
+
+# vim: set sts=2 expandtab sw=2 ai: