Index: trunk/server/fedora/config/etc/postfix/main.cf
===================================================================
--- trunk/server/fedora/config/etc/postfix/main.cf	(revision 2727)
+++ trunk/server/fedora/config/etc/postfix/main.cf	(revision 2728)
@@ -39,3 +39,4 @@
 # will add the wrong value here.
 inet_protocols = all
+# note: as of 21 Oct 2015, our IPv6 addresses do not have rDNS and are rejected by Gmail
 smtp_address_preference = ipv4