Port Required to receive mail on exchange...

[zoldy]

I suspect I have a firewall issue receiving email... here is what is happening..

New install and everything works great internal (at the office) Had the ISP change the MX record and have confirmed this to be successfull.

I can send mail fine however users attempting to send to me get a time out message returned to them... the server did not respond.

I used an MX record utilty found on the internet and the IP address is correct however it says "no response"... Is there a port that I need to open on my firewall that could be causing this.

Currently I am using just a linksys DSL rounter as a firewall (soon to be replaced) however I would like to use it for a week or two.

Any suggestions would be greatly appreciated.

Thanks

 

[SteveTheGeek]

SMTP, port 25 (TCP)

-Steve

 

[zoldy]

Thank you...

 

[melgamal]

I have port 25 open and forwarding to the internal ip of exchange server 10.10.10.1 but still can't receive mail except if I publish my exchange server with a public ip address (the ip in MX record) (without firwall)

 

[SteveTheGeek]

That sounds to me like a firewall configuration problem, then. When the firewall is in the configuration, can you telnet to port 25 of your public IP address from somewhere on the internet?
-Steve

 

[melgamal]

no, I don't even get an error!

 

[melgamal]

even if I try to telnet 25 internally (thru the network name)

 

[SteveTheGeek]

If you telnet to 10.10.10.1 25 right now it doesn't come up with the Exchange SMTP ready message, but when you change your Exchange IP address to the external IP and telnet to that, it works? Are you sure you configured the IP settings on your NIC correctly?
-Steve

 

[melgamal]

no, it doesn't come up with exchange smtp ready message in both ways. I checked that telnet service is running, exchange is sending mail internally/externall but only receiving mail within the internal network

 

[SteveTheGeek]

Sorry, I misunderstood, I thought you said that when you connected the Exchange server directly to the internet without the firewall, you were able to recieve external mail. If you're not able to connect to the SMTP server either way, then check to see if the SMTP service is started, and if it isn't, check the event viewer logs to see why it isn't starting.
-Steve

 

[PScottC]

Mel --- You shouldn't need the telnet service on the Exchange server running. On an NT/2000/XP machine, you can specify which port you are telnetting to. If you look at Steve's message, the command is:
telnet 10.10.10.1 25

The <space 25> tells telnet not to use the usual port. Try again and let us know.

More than likely, the NAT settings are not right on your firewall. What type are you using? Linksys, PIX, CheckPoint? Also... are you sure that 10.10.10.1 is the Exchange box, 1 is usually used for a router or firewall's inside ethernet interface.

Apologies if I'm way off...

PSC

 

[melgamal]

Because I had to get exchange running back after the weekend, I removed the Linksys firewall, and exchange is working fine now (sending/receiving emails internally and externally)by having it public. But about the problem with telnet, I'm still unable to telnet to the server even internally.
telnet 10.10.10.1 25
I'm getting connection to host lost.
Note: I checked under services and found that telnet service is running
I'm suspecting that exchange telnet is not running or installed?
Not sure
Thanks

 

[SteveTheGeek]

melgamal,

Don't worry about the telnet service on the Exchange server. I suggested using a telnet &quot;client&quot; in order to connect to the SMTP Service, which would verify that the SMTP service is running. What do you get when you do the following:
telnet *fill in external ip address* 25

Can you ping either 10.10.10.1 or the external IP address?

Does your Exchange server have two network cards, or two IP addresses running on the same card?
-Steve