This is driving me up the wall.

I cannot telnet/paping port 25 on an a specific host/ip on one server. I can telnet/paping it from any other computer on the same network.

I have tried completely disabling the firewall.

I can ping the host normally (using the default ping command)

I can ping port 80 on the host.

There is nothing different about this server than other servers on the same network (it has the same default gateway, same dns servers)

I just can't ping this host or anything else on port 25.

Any ideas?

Edit I guess I need something like tracert that will tell me where the connection is being blocked.

Edit After too many hours of tearing my hair out I have found out that it is being blocked by Mcafee Antivirus on the local machine. I have added exceptions for cmd.exe and wscript.exe and I can now connect to the port.


It looks like it's being blocked by the antivirus software. If I disable access protection the ability to ping that port begins working immediately.

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It would help if you let us know what software you're using. In this particular case, it could be that your SMTP server has blacklisted you.

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  • They allow connections from other servers in the same network (so same public IP) so we cannot be blacklisted. As for software - It is a windows script that uses it but I'm now just trying to connect to it from windows command prompt using telnet and paping and neither will let me. they both work on other servers, same os, same dns, same default gateway, same network. – MrVimes May 16 '13 at 13:57

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