Exchange and Host Domain Unreachable

[Rookcr]

I need some advice. I am currently caught in the middle of a blame game and I am not sure where to go.

Here is the situation.

I am currently unable to send any e-mail to one specific domain. The messages are sitting in my Exchange message Que. Eventually they bounce back stating that the host is unreachable. This is only done for this one specific domain. From my exchange server I can perform an NSlookup of the mail server we arer trying to reach as well as a get the mx lookup. In addition from the router outside my firewall I am able to do a trace route back to the domains mail server. Is there a place in exchange 5.5 where somthing might have been set up that will not allow me to send e-mail to this domain???

I am open for any ideas.

Thanks,

The rookie.

 

[MRRue]

Hi I ran into the same problem 3 years ago, here are the steps i took to resolve the problem.
1.Try sending an email the problem domain from another email account such as hotmail, yahoo, if you get the same message then you know that the problem does not you server but the target domain.

2. Try and send email from your domain, when you recieve the NDR look at the header of the message it should give you some indication where the message failed.

3. Check your router/firewall and see if incoming/outgoing packets have been blocked for this domain.

In most cases i have found that the problem to be the target host exchange server.

thanks

Rue

 

[johnny99]

Here is one more.

Try to telnet to the host in the mx record at port 25
You should get an answer like this:

220 odin.joe.net ESMTP Sendmail 8.11.2/8.11.2; Thu, 13 Feb 2003 18:30:10 GMT

If you get this one what you have is at least a connection.
If you don't, the problem is in 99,99% of the cases in the receiving end and and not yours.

This type of problem regarding emails come up in most installations from time to time.
I have for years tried to tell management (in different companies) that using SMTP email is not the way to go if you want an email system you can trust 100%.
SMTP works most time, but not all the time.

What management want is a global x.400 system at the price of SMTP.
So when I am in the "wrong mood" I tell them they should get all people on the internet to switch from SMTP/POP3 email to x.400 (the users just have to pay at least USD 200 per mailbox per month each)