Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

Hello i am using hmailserver for W2008 R2 machine

I could pull my hair off on this. Request mail from server: OK, sending mail: ISSUE I can telnet pop3 110 | but cannot telnet port 25

First of all, mail client says (when attempting to send mail out): "Sending of message failed. The message could not be sent because the connection to SMTP server smtp.mydomain.com was lost in the middle of the transaction.

I deinstalled, re-installed hmailserver, tried othe mail servers as well, .. same issue. Tried all possible solutions to telnet port 25... no success, only telnet to 110 is fine. (yes, i can send request to mail server to check for mails on it) I tried disabling firewall, deleting + reopen ports 25,110.. no success.

Ping to mail server is ok as well.. no issue here as well. ISP does not block any ports.. i asked them for any netwok issue, no network issue I even de-installed yesterday installed Windows updates :(

MX, PTR's.. all DNS settings are resolved just fine, but when it comes to connect to SMTP server, for checkin mail delivery, connection is not possible.

PERFORMING A PORT SCAN:

25  smtp    Success 140 ms
53  dns Success 140 ms
80  http    Success 140 ms
110 pop3    Success 140 ms
8080    webcache    Success 140 ms

PERFORMING LOOKUP FOR PORTS IN USE (ip & server names are dummies):

Active Connections

    Proto Local Address Foreign Rddress    State
    TCP   0.0.0.0:25    OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:80    OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:110   OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:135   OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:143   OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:222   OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:445   OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:3306  OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:8080  OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:47001 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49152 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49153 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49154 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49156 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49157 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49210 OOOORO-RORORO:0 LISTENING
    TCP   0.0.0.0:49497 OOOORO-RORORO:0 LISTENING
    TCP   44.4.44.4:25  OOOORO-RORORO:0 LISTENING
    TCP   44.4.44.4:25      vmai1:64053    TIME_WAIT
    TCP   44.4.44.4:25      mai12:41276    TIME_WAIT
    TCP   44.4.44.4:25  mai1-p2B-f46:556B2 TIME_WAIT
    TCP   44.4.44.4:53  OOOORO-RORORO:0 LISTENING
    TCP   44.4.44.4:110 114.?9.52.54:343B1 TIME_WAIT
    TCP   44.4.44.4:139 OOOORO-RORORO:0 LISTENING
    TCP   46.4.24.4:49579 mucB3sB2-in-f19:http TIME_WAIT
    TCP   44.4.44.4:49580 fa-in-f154:http TIME_WAIT
    TCP   44.4.44.4:49581 95.100.86.22:http TIME_WAIT
    TCP   44.4.44.4:49590 www-14-B5-prn1:http TIME_WAIT

Is it normal that port 25 is accupied more than once?

Your big big help is really appreciated

share|improve this question
    
Forgot to tell that, changing to a different port for testing, it worked fine. I was able to connect to mail server and sent mails out. –  Grashopper Apr 12 '12 at 19:14
    
Can you capture a connection with tcpdump to find out when and where it disconnects? Or better yet, capture the same connection from both the client and server? And is there a firewall of any kind in front of the server? –  Shane Madden Apr 12 '12 at 19:21

4 Answers 4

The server is listening on port 25, so the issue lies elsewhere. Is it possible that your ISP or your internet firewall is blocking outbound port 25 connections? The test is this. If, from the server you can telnet to port 25, then the system is fine. If you cannot telnet from your desktop, something is blocking you.

For what its worth, we block, by default, all outbound port 25 traffic from our network.

share|improve this answer
    
Hi, no.. i have tried from different locations and computers. The firewalls are not blockin outbound connections. However, i am not able to telnet port 25.. from any computer –  Grashopper Apr 12 '12 at 19:57
    
Have you verified that IIS SMTP serverisn't listening on port 25 for 44.4.44.4? –  uSlackr Apr 12 '12 at 22:20

Try stopping the SMTP service and doing another port scan see if port 25 is still open.

Seems this works one a different port its most probably likely that something else is also running on the same port and clashing.

If that does not show anything. change the port again and see how many addresses it is listening on.

share|improve this answer
    
i stopped SMTP service run again a scan. I can see one entry now: TCP 44.4.44.4:25 0.0.0.0.0 LISTENING 860, where 860 are a bunch of services in Windows –  Grashopper Apr 12 '12 at 20:12
    
i can telnet localhost 25 but cannot telnet mail.mydomain.com 25 –  Grashopper Apr 12 '12 at 20:40
up vote 0 down vote accepted

It turned out that a secondary service was listenning to port 25, can't explain how this happend.probably during recent Windows update, something went wrong.

share|improve this answer

It's possible the SMTP server process had hung. Did you try restarting it?

It is odd that the SMTP server is listening both on any address (0.0.0.0) and a specific address (44.4.44.4) for port 25, but it is not unusual that there would be one listening socket and several established connections. This just means that something connected.

Check that there is not another process trying to listen on port 25 as well.

From your comments, it looks as though you have bindings both to UNSPEC (0.0.0.0) and to a particular address on port 25. In this case, inbound connections to the specific IP address 44.4.44.4 on port 25 will go to the listening socket of process 860 (eg. not to hmail). Connections bound for other addresses (such as 127.0.0.1) will go to process 2260's listening socket (eg. to hmail).

share|improve this answer
    
I tried that as well, seems that smtp service is running fine. Stopped and restarted it. however, doing a netstat -ano | findstr :25 shows that two (2) PID's are making use (well, that's what i think) 0.0.0.0:25 LISTENING 2260 + 44.4.44.4:25 LISTENING 860 (2260 is hmailserver, 860 are multiple other windows services) –  Grashopper Apr 12 '12 at 19:32

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.