--- src/mailman/config/postfix.cfg.orig	2017-08-10 03:04:28 UTC
+++ src/mailman/config/postfix.cfg
@@ -5,7 +5,7 @@
 # db file, from the associated plain text files.  The file being updated will
 # be appended to this string (with a separating space), so it must be
 # appropriate for os.system().
-postmap_command: /usr/sbin/postmap
+postmap_command: /usr/local/sbin/postmap
 
 # This variable describes the type of transport maps that will be generated by
 # mailman to be used with postfix for LMTP transport. By default, it is set to