Sendmail, Exchange, DNS and the web

[ManagerJay]

I have managed to get myself completely flustered with this problem and I am sure there is an easier way to accomplish what I am trying to do than what I am doing.

The organization I work for has decided to host the web site internally (up to this point it has been hosted by an outside company). One of the features of our web site is our members can fill out a form and have the information mailed to the appropriate employee to handle their issue.

The e-mail server used for the organization (Exchange) is behind a firewall and port 25 is forwarded to the Exchange server.

In order to avoid having to send e-mail back through the firewall and to avoid having employees going through the firewall to access the web site, I have two NICs in the web server. One has the external address scheme (199.XXX.XXX.XXX) and the other has the internal address scheme (10.YYY.YYY.YYY).

So, I was thinking that if a member fills out a form that is e-mailed to an employee, I can simply use the 10.YYY.YYY.YYY NIC and send e-mail directly to the Exchange server. I made the appropriate entries in /etc/hosts and then discovered that sendmail is only using information received from DNS queries to resolve the host name. I have also created an service.switch file, and modified sendmail.cf. Sendmail is still using DNS queries to resolve the name.

The error message I receive states the e-mail has been deferred because of a timeout communicating with the Exchange server. And, the IP address being used for the Exchange server the public IP address.

Is it possible to send an e-mail using the format user.name@10.YYY.YYY.YYY? If so, how is this done?

Is it possible to make sendmail query /etc/hosts and then DNS?

Or, have I just overcomplicated this problem, and there is an easier way to accomplish the same thing?

I am running RedHat 7.2 with Sendmail 8.11.

Thanks for your help.


Jay

 

[Bluedoor]

What you are doing should work, but the problem is sendmail is still using DNS to resolve. So try checking /etc/nsswitch.conf and make sure sendmail is not using it to resolve ?

 

[ManagerJay]

OK, I have everything talking to each other now. But, it appears the messages are just queued and not sent. Where do I look to determine if the messages are sent or have just been queued?

Thanks for your help.


Jay

 

[ManagerJay]

I have discovered everything is being sent to the Exchange Server and then the message is not delivered (a Non-Delivery Report is generated).

Thanks for your help and I will start pursuing this matter on the Exchange side.

Thanks again.


Jay

 

[Bluedoor]

Hi,

Sorry, I didn't get the chance to check this for couple of days. But to answer your first question, use the command "mailq" it will show you everything that's in queue.

You can delete what's in queue by going to /var/spool/mqueue and associating the the "Q ID" from the mailq command.

You're approach is right in that if the exchange server is not accecpting this mail, it has to be resolved from the exchange server side.

hope this helps, good luck ! Bluedoor
"Act without doing; work without effort."