How can I give ownership permissions for a distribution list (DL) to more than one person? I want individual list members to be able to add and remove themselves.

You usually think of a DL as having one owner. However, Exchange lets you use either one account or a group whenever a component requires an owner. To give multiple users ownership of a DL, put them all into a Windows NT global group, then assign the group as the DL owner.

One of my users needs to be able to send mail as another user, in such a way that the recipient can't tell. Send on behalf of didn't work. What else can I try?

Exchange/Outlook has two similar—but quite different—features: Send on behalf of and Send As. Send on behalf of means that the sender can send mail under the authority of another person. The Marine Corps calls this "by direction," because lower-level officers can sign a letter using their commanding officer's signature as long as they add "by direction" below the signature to signify that someone else was sending the letter. Outlook communicates this process by saying something like "Joe Davis on behalf of Paul Robichaux" on mail that a user sends using this option.

The permission you want is Send As. When you grant an NT account Send As permission on a mailbox, the holder of that account can send mail from the mailbox that is indistinguishable from mail sent by the primary mailbox owner. You set Send As permission in the mailbox Properties dialog box; don't forget that permission changes can take some time to propagate.

We use deleted item retention on all our mailboxes. Recently, I moved some users to a new server, and the move appears to have wiped out their deleted items cache. Is this behavior a bug?

No, this behavior occurs by design. When you move a mailbox to another server with the Tools, Move Mailbox command in the Microsoft Exchange Administrator program, Exchange removes that mailbox's items from the deleted items store. Microsoft implemented the feature this way to prevent unnecessary moving of outdated items, although the result can be disconcerting if you don't expect the deleted items to disappear. The most recent version of the Exmerge utility (available from Microsoft Product Support Services—PSS) offers an option to move a mailbox while preserving its deleted items stash; if this capability is important to you, contact PSS to obtain the software.

What's the best method for moving users from one site to another while preserving the source server's X.400 address?

You can't preserve a mailbox address in a move between sites. X.400 addresses are deeply embedded in all Exchange Server 5.5 objects, and mailboxes are no exception. When you move a mailbox between servers within a site, Exchange Administrator can rewrite the addresses for you. However, Exchange doesn't offer an automatic way to move users between sites because Microsoft never saw it as something users wanted to do and because of the technical problems of transferring mailbox contents in a reliable way between sites. If user A moves from server A in site A to server X in site Y, any stored mail on server A that refers to user A will have an incorrect address. To correct the address, you must either use Exmerge or manually export the mailbox contents to a Personal Folders (.pst) file, delete the mailbox, and recreate it on the target server. When you move an entire server, the Move Server Wizard uses the X.500 proxy redirection address to solve correct addresses.

In your February column, you mentioned some time synchronization methods. Why didn't you talk about the Network Time Protocol (NTP)?

I'm embarrassed that I omitted NTP because I use NTP on my network—a mix of UNIX, Mac OS, and Windows machines. NTP is an Internet-standard protocol for time synchronization on private networks or the Internet, and free NTP clients and servers are widely available. For more information, go to http://www.eecis.udel.edu/~ntp/ntp-spool/html/index.htm. (Thanks to alert readers James Bart and Tim FitzPatrick for catching my goof.)

How can I use Exchange as a mailing list server?

Because Exchange is so powerful and flexible, you might be tempted to see it as the solution to every need. Although you might think Exchange would make a good mailing list manager, no product measures up to the standard set by the free, well-understood, and widely available Majordomo package for UNIX machines (http://www.greatcircle.com/majordomo). The Microsoft BackOffice Resource Kit (BORK) contains Exlist, an unsupported mailing list manager, and some third parties sell software (e.g., L-Soft's LISTSERV) that purportedly works with Exchange. My recommendation: If you need a mailing list solution, dedicate a machine to the task and have it run either Majordomo or a package such as Gordano's NTList. Don't try to make Exchange do something it doesn't do well. However, Tony Redmond's "Using Exchange Server as a List Server," May 1999, describes how you can obtain list server functionality from Exchange if you want to give it a try. (Thanks to reader Thelma Benison for this question.)

We're about to run out of disk space on our Exchange Server 4.0 Service Pack 5 (SP5) server. I had our users clean up their databases, but the priv.edb file didn't get any smaller after the scheduled Information Store (IS) maintenance task ran. Why didn't the priv.edb get smaller?

You're seeing the confluence of two separate phenomena. First, NT's management utilities (e.g., Windows Explorer and the command shell) can't accurately report the size of an open file. That means that if one of your .edb files grows or shrinks a great deal, just examining the file size won't show you that change unless you stop and restart the IS.

But why isn't your priv.edb file getting smaller? The answer is both simple and counterintuitive: It won't get any smaller. Ordinarily, the .edb files are like those little sponge pellets you buy for your kids. When you drop them in water, they expand into dinosaurs, birds, or whatever. You can't shrink the sponge back into its original pellet size. Microsoft designed the Exchange IS not to release space back to the file system because the database will likely grab back up any space the IS releases. You can force the IS to yield its free space by stopping the IS service and using Edbutil (with Exchange Server 4.0) or Eseutil (with Exchange Server 5.5) to perform an offline defragmentation. However, if space is really tight, perhaps now is a good time to add more disk space. (Thanks to reader Mark Dodd for this question.)

Can we integrate our Exchange servers with the SNMP tools we currently use to monitor and manage other servers on our network?

Ordinarily, to use a service with SNMP, you need a special database called a management information base (MIB). Exchange Server 5.5 supports the Mail and Directory Management (MADMAN) MIB, but the MADMAN standard lacks some useful features. Glen Darling (gdarling@epcor-group.com) has produced an MIB that lets you monitor your Exchange servers. You can get it from the Goodies & Links page at http://www.robichaux.net/writing/man-exchange.html.

How can I back up and restore configuration parameters for the Internet Mail Service (IMS)?

Restoring a crashed server by reinstalling NT and restoring the IS and Directory Service (DS) databases doesn't restore the IMS configuration information because the IMS keeps its configuration in the Registry. This behavior is a pain in the neck because you must manually restore the IMS settings to their original state. Fortunately, tools are available to automate this process. The Imcsave, Imccopy, and Imcrstr tools (all available in the server\support\utils\i386 directory on your Exchange Server 5.5 CD-ROM) let you back up and restore the IMS configuration and directory structure—in short, everything you need to clone a failed IMS. See the Microsoft article "XFOR: Imcsave Utility" at http://support.microsoft.com/support/kb/articles/q195/8/04.asp and the readme.doc file in the utility directory for details about how these tools work and what to do with them.