Hiya everyone,

I deployed a MDK box for a customer as a low cost/maintenance solution for simple file sharing between Mac OS9 and Windows boxes. That portion of the box is working well, and that is all that is configured, save the normal gamut of necessary services (Webmin). There is no mail, DNS, DHCP, or web server running on this box. Their router handles DNS DHCP duties for them.

My question is, is there any possible way that this simple box could break access to the customer's wail servers? Let me explain.

This server replaced a W2k box a week ago, the MAC and Windows machines are swapping files back and forth all day long. The customer has Outlook Express on the Macs and Outlook XP on the windows box, checking 3 different mail addresses provided by their web site host. Everything is working AOK till about Wednesday, when I receive a call from them stating they cannot send e-mail always receiving a message "Sorry, that domain is not allowed to be realyed by this MTA" "Error 5553". A little troubleshooting, and we find that they can send mail to other domains hosted by the same company (I have one hosted by the same company, so we used it to test). But sending to other domains such as hotmail.com or comcast.net, fail with the above message. At first I thought there was some configuration that was lost but we found this EXACT same problem is happening on all of their machines. So i am thinking their router has somehow failed, but the status bar of their mail clients indicate they have connected to the outgoing mail server, it is just drop kicking the message back. To make things more interesting, i took my Win XP laptop in there and was able to send and receive mail just fine, no matter who addressed to.

Now the web host insists that we do not have the "authentication required" option selected for each mail account outgoing mail server, when in fact we do.

Also, all mail is sent just fine using the hosts web mail interface, so while the problem appears to be server side, our troubleshooting has proven otherwise (XP laptop and webmail successfully sending all e-mails). Is there any one thing the MDK box could be doing to cause this? I have my doubts, but it sure makes me suspicious.

I have checked the configuration of the router, and disconnected the MDK box just for testing with no change in behavior. The MDK box is the ONLY network change in nearly a year.

I even created a brand new e-mail account to test, still seeing the failure.

Does anyone have ANY clue as to how to fix this one?

Thanks in advance.

RED

Well, After trying several different configurations and possible fixes for thsi problem, I decided to take a more aggressive approach. On the macs, i donwloaded and updated their version of Outlook Express (5.0.5 I believe) and applied SP 1 and 2 to the Outlook XP (office) installation on the Windows box.

This fixed the problem on the macs, but not the Windows machine.

Any clues as to why or if this is related to installation of the MDK9.2 box?

Thanks.

RED

If you have disconnected the MDK box from the network and the problem still persists, then it is not that box.

I would re-verify all of the authentication information on the Outlook XP boxes. Something could have changed. Delete the stored passwords and re-enter all of the information.

I'm not sure of the right names, but I have maybe a similar problelm.
I cannot send mail from my default account in kmail or evolution or opera.
(Created new accounts in kmail and opera to test this.)
In kmail I get an error message something like "server refuses to relay. Error 5.7.1"
This in response to a test message, myself to myself.
Evolution error message is the usual gibberish. Forgotten.
I can send mail from other account, one of which is my own domain name, the other is Opermail.

Thought it was my ISP, but now I wonder.

Anyone have any ideas?