Dssec.dat

ADUC doesn't list all properties in GUI. To change what properties to be listed, modify the file "systemroote\system32\dssec.dat".

Reply to meeting request gets NDR

Manager sends the meeting request and the attendees accept it and immediately they get and NDR stating "The following recipient(s) could not be reached" with a deleted user account's name in it.

This can happen if the deleted user had been delegated access to the managers mailbox and the check box which states "Send meeting requests and responses only to my delegates not to me" had been checked in outlook delegates tab.

In certain cases you would still see the check box ticked and grayed out even after the delegatee has been removed from the outlook setting. You could add someone else as a delegatee and then remove the tick and then remove the delegatee again to clear the checkbox.

SMTP Tar Pitting in Windows 2003 SP1

What is SMTP tar pitting?

Tar pitting is the practice of deliberately inserting a delay into certain SMTP communications that are associated with spam or with other unwanted traffic. To be effective, these kinds of communications typically rely on generating a high volume of traffic. By slowing an SMTP conversation, you can dramatically reduce the rate at which automated spam can be sent or at which a dictionary attack can be conducted. Legitimate traffic may also be slowed by tar pitting.

The tar pit feature is available in Microsoft Windows Server 2003 and in several third-party SMTP servers. The tar pit feature in Windows Server 2003 works by slowing all responses that contain SMTP protocol 5.x.x error codes.

Tar pitting is a feature of Windows 2003 so Exchange 2000 can benefit too.

http://support.microsoft.com/default.aspx?kbid=842851