We recently installed an Exchange 2010 Server and we are having some problems sending emails to certain domains. One domain we are having problems with is nnwcpa.com. Email is stuck in the queue with 4.2.2 Connection dropped due to SocketError.
When I telnet to nnwcpa.com 25 from our email server it connects but as soon as a try and type any commands it disconnects. It appears to be something with our email server because I can telnet to nnwcpa.com 25 from a different computer and it connects and I can issues commands without being disconnected.
I also noticed when I telnet to nnwcpa.com it connects to there email hosting service navi2.webnethost.net. I tried telneting directly to navi2.webnethost.net from our email server and I was able to connect and issues commands but if I use the nnwcpa domain it disconnects me again.
Any ideas on what the problem could be?
I have disabled 2008 Server Firewall, Forefront Security and just about every advanced feature on the Broadcom nic but nothing has helped.
All the domains we have issues with are hosted on Exim email servers.