disable nested checker checks (#972)

fixes #967

CHANGELOG.md

@@ -14,6 +14,10 @@ System:
 
 * Lower memory requirements to 512MB, display a warning if system memory is below 768MB.
 
+Mail:
+
+* Turn off header filters for forwarded email.
+
 v0.20 (September 23, 2016)
 --------------------------
 

setup/mail-postfix.sh

@@ -91,7 +91,8 @@ tools/editconf.py /etc/postfix/main.cf \
 # * Give it a different name in syslog to distinguish it from the port 25 smtpd server.
 # * Add a new cleanup service specific to the submission service ('authclean')
 #   that filters out privacy-sensitive headers on mail being sent out by
-#   authenticated users.
+#   authenticated users.  By default Postfix also applies this to attached
+#   emails but we turn this off by setting nested_header_checks empty.
 tools/editconf.py /etc/postfix/master.cf -s -w \
 	"submission=inet n       -       -       -       -       smtpd
 	  -o syslog_name=postfix/submission
@@ -100,7 +101,8 @@ tools/editconf.py /etc/postfix/master.cf -s -w \
 	  -o smtpd_tls_ciphers=high -o smtpd_tls_exclude_ciphers=aNULL,DES,3DES,MD5,DES+MD5,RC4 -o smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3
 	  -o cleanup_service_name=authclean" \
 	"authclean=unix  n       -       -       -       0       cleanup
-	  -o header_checks=pcre:/etc/postfix/outgoing_mail_header_filters"
+	  -o header_checks=pcre:/etc/postfix/outgoing_mail_header_filters
+	  -o nested_header_checks="
 
 # Install the `outgoing_mail_header_filters` file required by the new 'authclean' service.
 cp conf/postfix_outgoing_mail_header_filters /etc/postfix/outgoing_mail_header_filters