Exchange 2013 SP1. Edge transport. How to solve problems with ipv6 when sending mail to external domains?

Question

Domain Name System

Hello!
Testing Exchange 2013 SP1 (with new transport role). When sent outside, for example to gmail.com, letters hang in the queue for 5 minutes. With an error:
451 4.4.0 DNS query failed. The error was: DNS query failed with error ErrorTimeout.
There are also errors in the ConnectivityLogPath log:

2015-04-15T08:59:28.389Z,08D24559874DD7AB,SMTP,gmail.com,>,"gmail-smtp-in.l.google.com[2a00:1450:4010:c05::1b, 64.233.165.26], alt1.gmail-smtp-in.l.google.com[2404:6800:4008:c02::1a, 74.125.23.26], alt2.gmail-smtp-in.l.google.com[2404:6800:4008:c01::1a, 173.194.72.26], alt3.gmail-smtp-in.l.google.com[2607:f8b0:4..."
2015-04-15T08:59:28.389Z,08D24559874DD7AB,SMTP,gmail.com,>,Failed connection to 2a00:1450:4010:c05::1b:25 (NetworkUnreachable:00002743)[TargetIPAddress:2a00:1450:4010:c05::1b:25|MarkedUnhealthy|FailureCount:1|NextRetryTime:2015-04-15T09:00:28.389Z]
2015-04-15T08:59:28.389Z,08D24559874DD7AB,SMTP,gmail.com,-,Messages: 0 Bytes: 0 (Attempting next target)
2015-04-15T08:59:28.389Z,08D24559874DD7AE,SMTP,gmail.com,+,DnsConnectorDelivery 72195e2b-eaa2-44f0-ab14-8b7353ead22a;QueueLength=TQ=0;RN=1;
2015-04-15T08:59:28.482Z,08D24559874DD7AE,SMTP,gmail.com,>,Established connection to 64.233.165.26

I’ll make a reservation right away, we don’t have external ipv6. We don't use it inside either.
Googled the error.
Tried the following:
1) HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\
DisabledComponents=0xffffffff
2) set-transportservice TRANSPORT -ExternalIPAddress xxx.xxx.xxx.xxx
Didn't help. What other ways could there be to remedy this problem. As I understand it, the problem is that nslookup mx of the gmail.com record gives out ipv6 addresses to which the transport server tries to connect, but cannot because it does not have ipv6. And having tried several options, it all the same comes to the ipv4 address and connects.

Answer 1

tunnel broker. Not? =))

Answer 2

If still relevant, the problem is probably that your IPv6 address does not have a correct PTR record in DNS, which Google swears at.
As a solution to the problem - try to remove the IPv6 address from the SMTP Send Connector, leave only IPv4. Perhaps it can help.