Question : Sendmail to excahnge server

I am currently using sendmail and use smart relay to an exchange 5.5 server.  In sendmail.cf i have DS192.168.1.92 which points to an exchange 5.5 server.  We are upgrading to Exchange 2003 and the .92 server is going away. I tried changing to the 2003 exch server address DS192.168.1.24 and restarted everything but it now will not send. I added the IP address of the HP box to be allowed to relay from the SMTP Virtual server in Exchange System Manager.  The following is the error I get when trying to send out an email.  I kind of assume it has to do with DNS but why did it work with Exchange 5.5 and fail with Exchange 2003.

Message 19/21047 Mail Delivery Subsystem

Date: Wed, 28 Nov 2007 18:56:12 -0500 (EST)
To: root@tandc.
Subject: Returned mail: Service unavailable
Auto-Submitted: auto-generated (failure)

[Attach #1: ""]
[Type: text/plain, Encoding: 7bit, Size: 336]

The original message was received at Wed, 28 Nov 2007 18:56:12 -0500 (EST)
from root@localhost

   ----- The following addresses had permanent fatal errors -----
[email protected]

   ----- Transcript of session follows -----
... while talking to 192.168.1.24:
>>> HELO tandc.
<<< 501 5.5.4 Invalid Address
554 Service unavailable

[Attach #2: ""]
[Type: message/delivery-status, Encoding: 7bit, Size: 293]

Reporting-MTA: dns; tandc.
Arrival-Date: Wed, 28 Nov 2007 18:56:12 -0500 (EST)

Final-Recipient: RFC822; [email protected]
Action: failed
Status: 5.5.0
Remote-MTA: DNS; 192.168.1.24
Diagnostic-Code: SMTP; 501 5.5.4 Invalid Address
Last-Attempt-Date: Wed, 28 Nov 2007 18:56:12 -0500 (EST)

[Attach #3: ""]
[Type: message/rfc822, Encoding: 7bit, Size: 433]

-- Start of included mail.
Return-Path:
Subject: test 656
To: [email protected]
Date: Wed, 28 Nov 2007 18:56:11 -0500 (EST)

test 656

-- End of included mail.

Answer : Sendmail to excahnge server

As far as I can see the problem is with the name of your linux box. It is named "tandc." which the Exchange SMTP server does not like because of the ending ".".

Make your linux box a part of a domain so that its name will be "tandc.domain.com" or whatever and I believe that your problem will be solved.