diff --git a/setup/mail-postfix.sh b/setup/mail-postfix.sh
index eab152fb..24969513 100755
--- a/setup/mail-postfix.sh
+++ b/setup/mail-postfix.sh
@@ -70,10 +70,16 @@ tools/editconf.py /etc/postfix/main.cf \
 	bounce_queue_lifetime=1d
 
 # Guard against SMTP smuggling
-# This short-term workaround is recommended at https://www.postfix.org/smtp-smuggling.html
+# This "long-term" fix is recommended at https://www.postfix.org/smtp-smuggling.html.
+# This beecame supported in a backported fix in package version 3.6.4-1ubuntu1.3. It is
+# unnecessary in Postfix 3.9+ where this is the default. The "short-term" workarounds
+# that we previously had are reverted to postfix defaults (though smtpd_discard_ehlo_keywords
+# was never included in a released version of Mail-in-a-Box).
+tools/editconf.py /etc/postfix/main.cf -e \
+       smtpd_data_restrictions= \
+       smtpd_discard_ehlo_keywords=
 tools/editconf.py /etc/postfix/main.cf \
-	smtpd_data_restrictions=reject_unauth_pipelining \
-	smtpd_discard_ehlo_keywords="chunking, silent-discard"
+       smtpd_forbid_bare_newline=normalize
 
 # ### Outgoing Mail
 
diff --git a/tools/editconf.py b/tools/editconf.py
index 0438695b..db19e5f1 100755
--- a/tools/editconf.py
+++ b/tools/editconf.py
@@ -30,7 +30,7 @@ import sys, re
 
 # sanity check
 if len(sys.argv) < 3:
-	print("usage: python3 editconf.py /etc/file.conf [-s] [-w] [-c <CHARACTER>] [-t] NAME=VAL [NAME=VAL ...]")
+	print("usage: python3 editconf.py /etc/file.conf [-e] [-s] [-w] [-c <CHARACTER>] [-t] NAME=VAL [NAME=VAL ...]")
 	sys.exit(1)
 
 # parse command line arguments