Hello,

I have Exchange 2010 server and new Exchange 2013 which I have installed recently.<o:p></o:p>

When I create a new mailbox using Exchange 2013 Database I am not able to send
external/internal e-mails, but I can receive them from outside and inside my
organization. <o:p></o:p>

As far I as I know when Exchange 2013 is installed with Exchange 2010, it inherits send
connectors and everything must be okay with sending e-mails.<o:p></o:p>

What might that be? Did I miss something?<o:p></o:p>

On exchange server you will need to enable send connectors normally

do you get any postmaster returned email? if so could you please allow us to see the error?

Have you opened an A record on Active directory DNS pointing to exchange server ?

• Edited by Bulent Sahin 23 hours 40 minutes ago added extra info

Thanks for reply,

On which exchange server?

No, Unfortunately I don't get any postmaster returned e-mails, all I have is few e-mails stuck in queue  

Hi ,

I hope you would be having a separate send connector to send emails to internet.If so please make sure the exchange 2013 server is also added as one of the server in the send connector's source server list.

What is the last error message on the exchange 2013 queue viewer ?

Did you exchange servers are directly sending emails to internet or else by using the smarthost? 

Exchange server 2013 did you enable send connectors on that server?

Are you using Network load balancing ( NLB) for exchange 2010 and 2013 in DNS where mail records pointing to...

Please check your DNS settings..

• Proposed as answer by Bulent Sahin 22 hours 54 minutes ago

Hi ,

Have you checked my suggestions ?

I have a common Send connector where Exchange 2010 and Exchange 2013 are added as the sorce servers. Do you think I need to add another one?

This is the error message:

When I try to send it to my gmail account

DnsConnectorDelivery "[{LRT=2/23/2015 4:33:50 AM};{LED=441 4.4.1 Error encountered while communicating with primary target IP address: ""Failed to connect. Winsock error code: 10051, Win32 error code: 10051."" Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 2607:f8b0:4003:c07::1a:25};{FQDN=gmail.com};{IP=2607:f8b0:4003:c07::1a}]

and there is another one

"SMTP Relay to Mailbox Delivery Group" "[{LRT=2/23/2015 4:43:53 AM};{LED=451 4.4.0 Primary target IP address responded with: ""451 5.7.3 Cannot achieve Exchange Server authentication."" Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was 10.110.110.34:25};{FQDN=Exchange2010.mydomain.com

Yes, I send e-mails directly without smarthost

Hi ,

First of all really sorry for my delay.

1.For the first error message please have look in to the below mentioned thread and it is purely related to dns related issue.

https://social.technet.microsoft.com/Forums/exchange/en-US/b067278e-391d-4622-87d3-a36881fa1b97/error-sending-emails-to-internet-failed-to-connect-winsock-error-code-10051?forum=exchangesvrsecuremessaging

2.For the second error message , it seems like the exchange server authentication is unchecked on the receive connectors in exchange 2013 and by default it will be checked .If you have done any changes on the default receive connectors please revert it back to the previous settings.

One more possible cause for the second issue was discussed on the below mentioned article.

http://msexchangeguru.com/2013/08/03/e2013-2010mailflowissue/