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I installed third party application on my Windows 2008 server to turn it into a mail server (MDaemon)...
I filled the info during its wizard very carefully without any changes in its options or preferences!
I configured it's IIS to use webAdmin and webClient and every thing is ok about them...
also this server acts as a web server (IIS and DNS are installed).

I turned my server and my pc firewall off...(both firewalls are node 32)

Executing these commands on the server are ok : 

telnet ip-address of server(127.0.0.1 on server) 25  
telnet ip-address of server(127.0.0.1 on server) 110  
telnet ip-address of server(127.0.0.1 on server) 143

but those commands fail on my local machine far away from that server!
What does that mean and what can I do to fix that?
I am system web developer , so I would appreciate some explanation about this situation!

Bart Silverstrim
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SilverLight
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3 Answers3

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If you are running into the failed connection attempts from a remote system, then the firewall on the server may require configuration for those ports.

If the failed connection attempts are occurring while on the server itself (via 127.0.0.1), then the server services themselves may not be running.

user48838
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  • thanks for answer -> the firewall of server is nod 32 and i turned it off .but still connection faild from my pc about this command : telnet 188.121.155.126 25 / i am using adsl internet... is this issue related to my isp ? – SilverLight Sep 03 '11 at 10:13
  • also would be appreciate to tell me which posrts should i open in node 32? (and what these ports mean ?) – SilverLight Sep 03 '11 at 10:13
  • TCP Ports 25 (SMTP)/110 (POP3)/143 (IMAP) should be opened on the server firewall and the router (if you want the server to be accessible from the Internet/another network). What are the telnet results when (telnet 127.0.0.1 [port number]) is attempted from the server itself? – user48838 Sep 03 '11 at 10:18
  • What are the telnet results when (telnet 127.0.0.1 [port number]) is attempted from the server itself? -> all of them are ok from the server / but faild from my personal computer(telnet 188.121.155.126 25) -> is that mean that i can't send any mail to that server or the others too? – SilverLight Sep 03 '11 at 10:25
  • That is a strong indication that a firewall on the server is still active. You might also verify that the built-in Windows firewall is either not running or properly configured. – user48838 Sep 03 '11 at 10:28
  • i turned both of them off (windows firewall and node 32) in both server and my pc - at this time telnet 188.121.155.126 25 faild from my pc - but 110 and 143 are ok / what is going on about 25? (however you were right about windows firewall - thanks) – SilverLight Sep 03 '11 at 10:46
  • Some desktop anti-virus will intercept port 25 as they "protect" the system. You might also try telneting to the IP of the server directly while troubleshooting to simplify/narrow the testing. – user48838 Sep 03 '11 at 11:09
  • let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/1275/discussion-between-lostlord-and-user48838) – SilverLight Sep 03 '11 at 11:21
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If I read the description correctly, you can telnet to the ports ON the server (locally) without a problem, but your remote machine can't get to the ports.

That would imply that there is a firewall blocking the connection or the ports are not configured for machines outside localhost to connect to them.

To see if the ports are open at all, you can run a portscanner like Nmap from your remote machine to the server to see what ports are showing up as open.

On the server itself you should be able to verify that the ports are open and attached to processes by running Netstat.

If Netstat on the server says the ports are open (and listening to your server's IP address interface, not JUST 127.0.0.1) then the next step is to diagnose either a lingering firewall issue or that the processes themselves are blocking outside access. Mail servers by default tend to block outside connections until they're configured to accept mail for the proper interface/domain, since otherwise they're spam-relay targets.

After that you should verify that your client and server actually see each other (ping, traceroute) on the network and verify this isn't a connection issue.

After that...I might look at a network dump using something like Wireshark to see if there's an issue with the handshake. Are the machines actually seeing each other, or is there a routing issue?

Bart Silverstrim
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  • really thanks for answer / as i said i turned both windows firewall and nod 32 in both server and remote machine / at this time server and remote machine can see each other by ping / 25 , 110 , 143 telnet on server are ok / 110 , 143 telnet from remote machine are ok - but 25 telnet from remote machine failed / why ? – SilverLight Sep 03 '11 at 10:59
  • Port 25 inbound traffic is blocked by many ISPs to prevent users from running their own mail servers and becoming spammers. – Keith Stokes Sep 03 '11 at 12:23
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Error when I telnet localhost 143 : Could not open connection to the host on port 143

My server is exchange server 2003.

How this was resolved: Open Exchange System Manager Administrative Groups First administrative group Servers Mailserver Protocols IMAP4 Start the Default IMAP4 virtual server if not started. Restart if already started.

In my case, I saw the Default IMAP4 virtual server in down position.

Hope this help someone.

Olarinre Jimoh
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