Problem with Internet e-mail over MS exchange server -FIXED

[Ark]

Small company network with MS Exchange Server 5.5, NT 4 server.
HTTP access working fine on all clients
All client computers (Win98) can access their local mailboxes.
But only some client computers can access Internet e-mail accounts POP3.
Telnet sessions to POP3 servers to port 110 have the same result: only some of computers have POP3 access, but all can telnet to local POP3 mailboxes.
Problem is not user dependent ? same user can login on the different PC and get POP3 access.

For TCP/IP client settings:
IP 10.X.Y.Z
Subnet 255.255.0.0
Gateway 10.X.1.1
WINS 10.1.1.1
DNS disabled
One important thing: these computers also can?t ping any IP address outside.

Any ideas? Any setting or registry tweaks?

 

[office boy]

<< One important thing: these computers also can?t ping any IP address outside >>


Is this a new problem or how they are setup?

 

[Ark]

<< << One important thing: these computers also can?t ping any IP address outside >>

Is this a new problem or how they are setup? >>



this is not a problem, may be just a key to the clue.
Workstation setup TCP on NIC is listed above

 

[office boy]

Well if DNS is disabled, you will need to have the full POP3 address. You don't just have mail in there do you? (It should be mail.server.com or something like that.) (actually thinking about that, if DNS is disabled, you should need the actual IP of the POP3 server)

I'm still a bit confused about how a computer with no Internet access can be expected to get email. If it can't ping, it would stand to reason that it can?t connect to the POP3 server.
Unless? Is the exchange server the POP3 server?

I do have to admit, I don't have an Exchange server here where I admin, I'm somewhat partial to MS mail. (it's just so damn easy

 

[Ark]

Office boy
Thanks fo quick response.
Yes DNS is disabled, I was told that WINS will do the same, but I am not sure.

I did direct IP, instead of address.
Example: mail.telocity.com has IP 216.227.56.40
So I am trying on my PC and laptop telnet 216.227.56.40 110, according to MS reccomendations http://support.microsoft.com/support/kb/articles/q165/1/86.asp
- can't get access.
Going to next office, logging on there - can do telnet with same pop3 server.

For HTTP access I have IE LAN settings to proxy server http://<server> port 80.

 

[office boy]

To telnet into a site, it would stand to reason that you need to be able to ping that site also.
Therein lies your problem IMO

 

[Ark]

This is what I thought too, why I can't ping any WAN IPs?
What can prevent it. This is not just one WS, I have at least 3 of them now and I did not check at least 10 more PCs.

 

[office boy]

Is your gateway configured for NAT properly?
What software are you using?

 

[LordOfAll]

OK you got some issues here.

1. Telneting to port 110 to a machine on the internet may not work. Most likely they have a firewall blocking the telnet port. You have to telnet to a known pop3 server that isn't behind a firewall.

2. Why such a large subnet for a small company?

3. DNS and WINS are not interchangeable. WINS is a Microsoft proprietary standard. You must be getting DNS info somewhere though, because http works. Unless you are using the IP directly, which I doubt. How are you connected to the internet and how are you sharing?

4. Gateway 10.x.1.1, with the subnet you picked you should have all the clients start with 10.x. Normally I wouldn't bring something so simple up but you have your WINS server on a different subnet, so I thought I would mention it.

5. If you can't ping outside with some machines how exactly is http working fine on them?

 

[Ark]

Office Boy:


<< Is your gateway configured for NAT properly?
What software are you using? >>


As far as I know software is MS Exchange Server 5.5 was installed last week on NT4 server. This server has additional network card connected directly to DSL modem. People who support our net had installation done for server and one WS only - now my boss and I should do the rest.
LordOfAll


<< 1. Telneting to port 110 to a machine on the internet may not work. Most likely they have a firewall blocking the telnet port. You have to telnet to a known pop3 server that isn't behind a firewall >>


Why is it working on some PCs, and doesn't work on others.


<< 2. Why such a large subnet for a small company? >>


This beyond my knowledge - my boss and support people determined that. we have around 25 PCs with 2 NT servers, only some of them will have internet access



<< 3. DNS and WINS are not interchangeable. WINS is a Microsoft proprietary standard. You must be getting DNS info somewhere though, because http works. Unless you are using the IP directly, which I doubt. How are you connected to the internet and how are you sharing?
>>


like I said above : DSL modem to NT server (dedicated NIC),MS Exchange server,
Each IE has settings - hever dial connection, LAN set to proxy http://<NTservername> port 80 and http working fine. (I am typing this)


<< 4. Gateway 10.x.1.1, with the subnet you picked you should have all the clients start with 10.x. Normally I wouldn't bring something so simple up but you have your WINS server on a different subnet, so I thought I would mention it. >>


Actually we have 2 separate networks (2 LAN cards+ 3rd for DSL modem) 10.1.x.x and 10.2.x.x. WINS sever is 10.1.1.1. but second network has 10.2.1.1 gateway and all PCs have 10.2.x.x iPs



<< 5. If you can't ping outside with some machines how exactly is http working fine on them? >>


I don't understand this too.
Like I said before some PCs are fine, example 2 identical Dell laptops - one is fine one is not.

Thanks guys for your help

 

[office boy]

I though Exchange was mail server software, not NAT software...

 

[Ark]

I think this is MS proxy server v2.x, but I am not sure, have to ask.

 

[LordOfAll]

Hmmm

well I'm not privy to some of your design decisions but some of the choices made are curious. Anyway, what I would do is gather some info on the working and non working PC's, tabulate it and compare to see if I could see a pattern. Info like IP #, subnet, default gateway, wins server, and some routing tables from each. But it sounds to me like a gateway problem.

 

[Ark]

<< ... and some routing tables from each >>


What routing tables should i compare? All other settings are checked many times (TCP/IP for NIC on each WS)

 

[GPooba]

This might not be helpful at all, but have you check the settings on the client computers? If the web browsers are set up to use a proxy, is it possible that on some computers the mail client software is configured differently than on the other computers? For example some proxy servers, to propogate pop3 correctly, require the SMTP server setting in the client to point to the proxy and then the account name to be name#popServer.

I hope this helps.

 

[LordOfAll]

WS routing tables. look specifically at the 0.0.0.0 line.

 

[Santa]

Another thing to not rule out is hardware related issues. I have sometimes had cable/NIC problems that caused weird Network problems. If you have identical parts and can't figure out the software side try hardware.

 

[Ark]

Thanks guys, will try it on monday.
I don't think that this is hardware related, I have tried different NIC, same results.

 

[LordOfAll]

Whoa! The freakin window is different! anyway

You mentioned 2 Dell laptops, one works and one doesn't. If you switch their IP's qhat happenes? The the access goes with the IP that is one type o problem. If access stays with the PC no matter what IP it has that is another type. This may help you norrow the problem a bit.

 

[Ark]

LordOfAll:
If I switch IPs problem stays with PC, so looks like this is PC configuration.
BTW laptops absolutely identical, made the same day 3 months ago,
but NICs are different:
- &quot;good&quot; has SOHO 10/100 PCMCIA,
- &quot;bad&quot; linksys 10-base-T, both going to the same hub (10/100).
Tried 10/100 linksys - no luck.

What else I need to compare except TCP/IP for NIC?
The &quot;good&quot; laptop has also dial-up account set (assing IP automatically+2DNS servers) but phone line is disconnected. The &quot;bad&quot; laptop doesn't have diail-up adapter installed, only client, NIC, and TCP/IP

 

[Ark]

Thanks everyone who helped us - problem fixed!

This is whats happened - network guys did not set Proxy Client on some local workstations or did not set them correctly. Reinstalled and all works fine!