Port 25 SMTP issue & server was lost in the middle of the transaction

windows-firewallwindows-server-2008windows-server-2008-r2

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

Best Answer

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.

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