Note that only one of the Sysvinit or Systemd startup files is needed

systemd-units/mailmunge-multiplexor.service.in

@@ -1,3 +1,7 @@
+#
+# NOTE: You should use only *one* of the SysVInit script or Systemd units;
+# it is acceptable to delete whichever you are not using
+#
 [Unit]
 Description=Mailmunge E-mail Filter (Multiplexor)
 Documentation=man:mailmunge-multiplexor(8)

systemd-units/mailmunge.service.in

@@ -1,3 +1,7 @@
+#
+# NOTE: You should use only *one* of the SysVInit script or Systemd units;
+# it is acceptable to delete whichever you are not using
+#
 [Unit]
 Description=Mailmunge E-mail Filter
 Documentation=man:mailmunge(8)

sysvinit/mailmunge.in

@@ -1,5 +1,8 @@
 #!/bin/sh
-
+#
+# NOTE: You should use only *one* of the SysVInit script or Systemd units;
+# it is acceptable to delete whichever you are not using
+#
 ##########################################################################
 # Copyright (C) 2002, Roaring Penguin Software Inc.
 # Copyright (C) 2021, Dianne Skoll