Telnet to port 25?

[eightball]

I have exchange 5.5 and I cant telnet to port 25. I always use it in trouble-shooting exchange. I tried from internet and at home. The wierd thing is I still get Internet mail perfectly. I was under the impression this had to open to recieved internet mail. Does anyone know why? is it a service pack thing?

 

[Maruis]

Not as far as I know.
Is your mailserver behind a firewall? If so you have to check your settings to determine if you are allowed to go to port 25 on your mailserver from outside your firewall.

Hope this helps

 

[Guest_imported]

You didn't state if you built this server or not, so I'll start from the beginning.
1.There could be a mail sniffer that is checking for viruses and the mail server is actually on a different port.
Internet--25-->virus sniffer--8777-->exchange server
2. There could be a firewall that is "Cleaning Up' the port listener and is waiting for you to send a HELO command.
3. The mail could be processed upstream at an ISP and sent privatly to the exchange server on a secret port or set to only receive from the ISP's server address.
4. There may be NAT on the firewall and the IP that is allowing port 25 is different than the Exchange server's external IP.

First look at the MX Records and see where mail is going to to find if it is going direct to the server's IP. Then check the firewall config for port translation or restrictions. After that, try plugging into the segment that the exchange external interface is on and give yourself an unused IP from the same block and try telnetting to it.