Our exchange 2013 CU2 (CAS+MBX, Win2012) was sending emails to Internet using another server (a kerio email server) and outbound internet email was working as expected.
We have now removed the Kerio server, I also removed the kerio_Send_Connector I was using to send emails to internet and I also changed the email domain in Exchange to be authoritative. I created a new Internet send connector with default values, but the same bad behavior is present.
Our Exchange 2013 receives emails internally and externally with no problems. The problems are sending emails to Internet. I am suspecting something in the firewall but i need to do some more research.
If from the same Exchange server I telnet to an Internet email host:25 I do get the smtp banner but as soon as I start typing HELO/EHLO I get disconnected and errors are logged.
Errors when sending emails to any emails address (this is from an email sent to google, all others are the same):
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Remote Server at aspmx3.googlemail.com (74.125.136.26) returned '400 4.4.7 Message delayed'
7/1/14 9:52:44 a. m. - Remote Server at aspmx3.googlemail.com (74.125.136.26) returned '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 74.125.136.26:25'
We have now removed the Kerio server, I also removed the kerio_Send_Connector I was using to send emails to internet and I also changed the email domain in Exchange to be authoritative. I created a new Internet send connector with default values, but the same bad behavior is present.
Our Exchange 2013 receives emails internally and externally with no problems. The problems are sending emails to Internet. I am suspecting something in the firewall but i need to do some more research.
If from the same Exchange server I telnet to an Internet email host:25 I do get the smtp banner but as soon as I start typing HELO/EHLO I get disconnected and errors are logged.
Errors when sending emails to any emails address (this is from an email sent to google, all others are the same):
****
Remote Server at aspmx3.googlemail.com (74.125.136.26) returned '400 4.4.7 Message delayed'
7/1/14 9:52:44 a. m. - Remote Server at aspmx3.googlemail.com (74.125.136.26) returned '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 74.125.136.26:25'
****
I cannot find any references from such Winsock error that are related to Exchange 2013.
So far all email is being queued at the Exchange Server 2013. I am afraid to install CU3 and make things worse.
Thanks for your comments.