I see your point. How about below patch? it disables all third-party modules.
diff -r 2d42afeacc4f iRedMail/functions/packages_freebsd.sh
--- a/iRedMail/functions/packages_freebsd.sh Mon Sep 22 06:19:06 2014 +0800
+++ b/iRedMail/functions/packages_freebsd.sh Tue Sep 23 22:06:00 2014 +0800
@@ -611,8 +611,8 @@
# Nginx
cat > /var/db/ports/www_nginx/options <<EOF
OPTIONS_FILE_SET+=DEBUG
-OPTIONS_FILE_UNSET+=DEBUGLOG
-OPTIONS_FILE_UNSET+=FILE_AIO
+OPTIONS_FILE_SET+=DEBUGLOG
+OPTIONS_FILE_SET+=FILE_AIO
OPTIONS_FILE_SET+=IPV6
OPTIONS_FILE_UNSET+=GOOGLE_PERFTOOLS
OPTIONS_FILE_SET+=HTTP
@@ -643,11 +643,11 @@
OPTIONS_FILE_UNSET+=CACHE_PURGE
OPTIONS_FILE_UNSET+=CTPP2
OPTIONS_FILE_UNSET+=ECHO
-OPTIONS_FILE_SET+=HEADERS_MORE
+OPTIONS_FILE_UNSET+=HEADERS_MORE
OPTIONS_FILE_UNSET+=HTTP_ACCEPT_LANGUAGE
OPTIONS_FILE_UNSET+=HTTP_ACCESSKEY
OPTIONS_FILE_UNSET+=HTTP_AUTH_DIGEST
-OPTIONS_FILE_SET+=HTTP_AUTH_LDAP
+OPTIONS_FILE_UNSET+=HTTP_AUTH_LDAP
OPTIONS_FILE_UNSET+=HTTP_AUTH_PAM
OPTIONS_FILE_UNSET+=HTTP_AUTH_REQ
OPTIONS_FILE_UNSET+=HTTP_DAV_EXT
@@ -661,22 +661,22 @@
OPTIONS_FILE_UNSET+=HTTP_REDIS
OPTIONS_FILE_UNSET+=HTTP_RESPONSE
OPTIONS_FILE_UNSET+=HTTP_SUBS_FILTER
-OPTIONS_FILE_SET+=HTTP_UPLOAD
-OPTIONS_FILE_SET+=HTTP_UPLOAD_PROGRESS
-OPTIONS_FILE_SET+=HTTP_UPSTREAM_FAIR
-OPTIONS_FILE_SET+=HTTP_UPSTREAM_HASH
+OPTIONS_FILE_UNSET+=HTTP_UPLOAD
+OPTIONS_FILE_UNSET+=HTTP_UPLOAD_PROGRESS
+OPTIONS_FILE_UNSET+=HTTP_UPSTREAM_FAIR
+OPTIONS_FILE_UNSET+=HTTP_UPSTREAM_HASH
OPTIONS_FILE_UNSET+=HTTP_UPSTREAM_STICKY
-OPTIONS_FILE_SET+=HTTP_ZIP
+OPTIONS_FILE_UNSET+=HTTP_ZIP
OPTIONS_FILE_UNSET+=ARRAYVAR
OPTIONS_FILE_UNSET+=DRIZZLE
OPTIONS_FILE_UNSET+=ENCRYPTSESSION
OPTIONS_FILE_UNSET+=FORMINPUT
OPTIONS_FILE_UNSET+=GRIDFS
-OPTIONS_FILE_SET+=ICONV
-OPTIONS_FILE_SET+=LET
+OPTIONS_FILE_UNSET+=ICONV
+OPTIONS_FILE_UNSET+=LET
OPTIONS_FILE_UNSET+=LUA
OPTIONS_FILE_UNSET+=MEMC
-OPTIONS_FILE_SET+=MODSECURITY
+OPTIONS_FILE_UNSET+=MODSECURITY
OPTIONS_FILE_UNSET+=NAXSI
OPTIONS_FILE_UNSET+=PASSENGER
OPTIONS_FILE_UNSET+=POSTGRES