install_postfix_advanced.sh: add parameters for 'Postfix DSN Support' to file 'main.cf'.

install_postfix_advanced.sh

@@ -2387,6 +2387,45 @@ virtual_alias_domains =
    btree:/etc/postfix/virtual_alias_domains
 
 
+#======= Postfix DSN Support ============
+
+# 
+# Use the smtpd_discard_ehlo_keyword_address_maps feature if you wish to allow DSN 
+# requests from trusted clients but not from random strangers
+#
+#     smtpd_discard_ehlo_keyword_address_maps =
+#        cidr:/etc/postfix/esmtp_access
+#
+#     /etc/postfix/esmtp_access:
+#         # Allow DSN requests from local subnet only
+#         192.168.0.0/28      silent-discard
+#         0.0.0.0/0           silent-discard, dsn
+#         ::/0                silent-discard, dsn
+#
+#smtpd_discard_ehlo_keyword_address_maps =
+
+
+# If you want to disallow all use of DSN requests from the network, use the 
+# smtpd_discard_ehlo_keywords feature:
+#
+#    /etc/postfix/main.cf:
+#        smtpd_discard_ehlo_keywords = silent-discard, dsn
+#
+# 
+#
+# A case insensitive list of EHLO keywords (pipelining, starttls, auth, etc.) that 
+# the Postfix SMTP server will not send in the EHLO response to a remote SMTP client.
+#
+#
+#    Notes:
+#
+#        Specify the silent-discard pseudo keyword to prevent this action from being logged.
+#
+#        Use the smtpd_discard_ehlo_keyword_address_maps feature to discard EHLO keywords selectively.
+#
+#smtpd_discard_ehlo_keywords = silent-discard, dsn
+
+
 #======= Rate Limiting ============
 
 # anvil_rate_time_unit (default: 60s)