Exchange Server - Confused: Port 110 on Exchange Server

Asked By Chri

20-Oct-08 07:36 AM

I'm confused on something here.

Exchange 2003 server
Exchange Event (Manual)
Exchange IMAP4 (Manual)
Store (Auto), Started
Management (Auto), Started
MTA Stacks (disabled)
POP3 (disabled)
Routing Engine (Auto), Started
Site Replication (Disabled)
System Attendant (Auto), Started

We also use Symantec Mail Security for Exchange

mail comming in

Now, since we don't use POP3 here. I took the following line out of the
router's configuration  ip nat inside source static tcp 10.0.0.15 110 <ext
ip> 110 extendable

Now we do not receive mail.

netstat -an does not even show anything on 25 anymore, only 0.0.0.0: 25
0.0.0.0 LISTENING

It's like we are using POP3 for incoming mail. Unless Symantec Mail Security
requires it to function.

...or am I missing something?

20-Oct-08 08:23 AM

Are you using a POP3 Connector to pull mail from an ISP?
Where do the MX records for your domain(s) point?
--
Bharat Suneja
Microsoft Corporation
blog: exchangepedia.com/blog

This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for
newsgroup purposes only.
------------------------------------------

20-Oct-08 08:36 AM

Hi Bharat.

Negative on POP3 pulling from ISP, just an SMTP connector to forward mail
outbound.  MX record pointsto one of our static IP's.

20-Oct-08 09:24 AM

When you drop POP3 port from the fw config, can you still telnet to SMTP
port from outside?
Did you try sending a test message?
--
Bharat Suneja
Microsoft Corporation
blog: exchangepedia.com/blog

This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for
newsgroup purposes only.
------------------------------------------

20-Oct-08 09:39 AM

Telnet  results:

110 - Connection Established, black screen - flashing cursor
25 -   Connection Established , black screen - flashing cursor

I assume this has to do with whatever proxy service Symantec does. Not much
help for us there.

To verify internal:
Telnet internal:  Port 25 responds with Microsoft ESMTP
Telnet internal:  Port 110 responds with Could not open connection to host
on port

Documentation not useful for Symantec product. Will open a ticket there.

Any other troubleshooting suggestions?

20-Oct-08 07:14 PM

On Mon, 20 Oct 2008 06:39:03 -0700, Chris


Not really. Exchange accepts connections on port 25 on your LAN so
it's not the Exchange server that's a problem.

Can you connect from the firewall to the Exchange server on port 25?
What do the firewall logs show you about connections from the Internet
to port 25? Is the connection accepted? Is it sent to the IP address
of the Exchange server?
---
Rich Matheisen
MCSE+I, Exchange MVP

22-Oct-08 08:16 AM

Rich,

The following is the response from the router itself:

telnet 10.0.0.15 25
Trying 10.0.0.15, 25 ... Open
220 mycompany.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready
at  Tue, 21 Oct 2008 16:34:39 -0300

[Connection to 10.0.0.15 closed by foreign host]

telnet 10.0.0.15 110
Trying 10.0.0.15, 110 ...
% Connection refused by remote host

Weird.

22-Oct-08 08:33 AM

On Wed, 22 Oct 2008 05:16:00 -0700, Chris


Was that connection closed immediately, or after som long period of
time? Are you able to enter any commands at all? HELP, HELO, EHLO?



That's expected.


If the router can connect to Exchange on port 25 then it's a pretty
good bet that there's something in the router that's not linking the
external (WAN) IP/Port to the internal (LAN) IP/Port. Bad NAT maybe?
---
Rich Matheisen
MCSE+I, Exchange MVP

22-Oct-08 12:56 PM

Rich,

Termination was generated by the quit command, otherwise it just sat there -
waited 10 minutes or so.

telnet 10.0.0.15 25
Trying 10.0.0.15, 25 ... Open
220 company.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready
at  Wed, 22 Oct 2008 13:37:33 -0300
HELP
214-This server supports the following commands:
214 HELO EHLO STARTTLS RCPT DATA RSET MAIL QUIT HELP AUTH TURN ETRN BDAT VRFY
HELO
250 company.com Hello [Gateway Address]
EHLO
250-company.com Hello [Gateway Address]
250-TURN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250-X-EXPS GSSAPI NTLM LOGIN
250-X-EXPS=LOGIN
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-X-LINK2STATE
250-XEXCH50
250 OK
HELP
214-This server supports the following commands:
214 HELO EHLO STARTTLS RCPT DATA RSET MAIL QUIT HELP AUTH TURN ETRN BDAT VRFY
quit
221 2.0.0 company.com Service closing transmission channel

[Connection to 10.0.0.15 closed by foreign host]

22-Oct-08 02:38 PM

On Wed, 22 Oct 2008 09:56:01 -0700, Chris


Okay. I didn't see that in your previous reply. I forget what the
timeout is while it's waiting for the session to begin. IIRC it's ten
minutes (600 seconds), but it might be 15 (900 seconds).
---
Rich Matheisen
MCSE+I, Exchange MVP