This is for Exchange 2003. Periodically, all my workstations lose connection with the Exchange Server, or the SMTP fails temporairly. This happens for approximately 28 minutes, when magically all my workstations Outlook connects again without any user interaction. Nothing at all is being logged in the event viewer on the server that might indicate an error. Also, I know that it has nothing to do with the NIC card, because I am able to maintain network connection with the server during the problem, and have tested it throughly.
This happens about every 48 hours. And with nothing in the event viewer, I have no way of troubleshooting it. If you have any thoughts, please help.