We have an application on a Windows 2003 server which has been able to send emails back to a view once an action takes place on the website. This broke entirely altogether, I've begun to troubleshoot the network layer aspect and by running telnet destination-ip-address 25 I get a valid response about 50% of the time, the other 50% of the time telnet over port 25 fails with the generic error of;
Could not open connection to the host, on port 25: Connect failed
I can ping this IP address always, even when these telnet tests fail. When they work I can send test emails through them. I can tracert when it works and doesnt work.
I have tried other destination IP addresses as the SMTP test, to known good sources, these work in conjunction with the original IP address that I test or they both fail.
Our firewall doesn't prevent port 25 traffic from inside > outside. The AV software was disabled during my testing. No windows firewall.
The last significant change was that this server was clustered with another, then clustering was broken off. Another change was that the NIC cards were teamed, as this is an HP server.
Any helpful suggestions are greatly appreciated. Thanks for your time!
Could not open connection to the host, on port 25: Connect failed
I can ping this IP address always, even when these telnet tests fail. When they work I can send test emails through them. I can tracert when it works and doesnt work.
I have tried other destination IP addresses as the SMTP test, to known good sources, these work in conjunction with the original IP address that I test or they both fail.
Our firewall doesn't prevent port 25 traffic from inside > outside. The AV software was disabled during my testing. No windows firewall.
The last significant change was that this server was clustered with another, then clustering was broken off. Another change was that the NIC cards were teamed, as this is an HP server.
Any helpful suggestions are greatly appreciated. Thanks for your time!