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Exchange 2003 Outbound SMTP Issue

Posted on 2013-01-17
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Last Modified: 2013-01-21
I have an Exchange 2003 server that will receive emails and deliver to recipients, but nothing will go out of the SMTP server.

I have checked all of the SMTP settings and everything looks good, however I noticed I cannot telnet to port 25 from command line from the server.

I can from other workstations on the network.

I'm new to this client and not sure how everything is setup.  It was working fine until today.

They are using an IPCOP box as their firewall and I can't see anything in there that could be causing the problem as well as there are no local software firewalls.

Any Ideas?

Patrick
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Question by:truth_talker
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Expert Comment

by:cpmcomputers
ID: 38788436
Is the smtp service on the server actually running ?
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Expert Comment

by:Amit
ID: 38788438
Create a new SMTP connector and directly point to ISP smart host and check again. Don't forget to change the cost to least.
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Author Comment

by:truth_talker
ID: 38788470
SMTP is running and I can telnet to myself, but I can't telnet out to another SMTP from the server, but I can from other workstations.

So I'm figuring the smart host can't deliver the messages on port 25 since I can't even telnet to the smarthost on port 25 from the server .
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Expert Comment

by:Amit
ID: 38788485
check with isp one time.
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Author Comment

by:truth_talker
ID: 38788503
But other computers can communicate on port 25, so unless they blocked the MAC address of my server, I don't see where they could have blocked our public IP address.
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Accepted Solution

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cpmcomputers earned 500 total points
ID: 38788508
It Doesn't use another port for smtp say 587 or 2525 ?

Does it resolve DNS and send mail directly or use a smarthost connector

As above check with ISP If it was working til today obviously something has changed?
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Expert Comment

by:cpmcomputers
ID: 38788520
Sorry , Is authentication to the smarthost correct, if any. has it changed ?
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Author Comment

by:truth_talker
ID: 38788527
I don't have a smarthost that I can use because my IPS requires authentication.  I have tried to resolve by DNS which is the way it was setup, but that's still not working.

The thing that changed is before I could go to a command prompt and "telnet smtp.1and1.com 25" for example and it worked
today it won't.  However the other computers on the same network can.
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Expert Comment

by:Amit
ID: 38788547
Ask your ISP, if any IP changed happened recently.
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Author Comment

by:truth_talker
ID: 38788550
I can telnet to smtp.1and1.com on 587 or to smtp.google.com on 587, but nothing on port 25

I'm trying to figure out what is blocking/prohibiting port 25 outbound.
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Expert Comment

by:Amit
ID: 38788565
Do you have any other ISP smart host, change it to alternate ISP and check that is working or not.
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Author Comment

by:truth_talker
ID: 38788699
I'm working on getting another smarthost.  But if i can't telnet out to port 25 from command line, that tells me that port 25 is being blocked somehow.


So how will getting another smarthost help if even routing through DNS isn't working?
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Expert Comment

by:cpmcomputers
ID: 38788707
So port 25 works for the client Ip's through your firewall but not the server?

It must be a firewall setting somewhere then surely, either something on the server itself,
or a device between  the server and the internet where the server IP is either not included in the allowed range or is being blocked by a rule relating to port 25?

Can you set your server to use port 587 whilst you work this out  
Is this the only server on the network (SBS or similar?)
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Expert Comment

by:cpmcomputers
ID: 38788737
I note you say you are new to this client - predecessors have not pulled the plug somewhere in the service provision?
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Author Closing Comment

by:truth_talker
ID: 38803760
Ended up using a paid service for the smarthost and resolved issue.
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