If you need a list of your current user list and primary e-mail addresses for whatever reason, it’s an easy thing to carry out with Exchange 2010. No powershell required!
Step 1 – Open up the Exchange Management Console.
Step 2 – Go to the “Recipient Configuration” and click on “Mailbox” on the left hand section of the screen. Make sure the columns you want are displayed in the middle.
Step 3 – On the right hand section click “Export List”. It will bring up a save file dialog box. It will save it as a tab delimited text file.
Step 4 – You can copy and paste the contents of this file directly into Excel and it will divide everything up into each cell just fine.
If you keep your Active Directory relatively clean you’ll always have an up to date e-mail list to send out when needed, or an easy way to get user lists for the various network appliances that don’t have LDAP connectivity.
It’s also worth noting that a lot of the lists in Exchange 2010 (and probably Exchange 2007) can be exported in this fashion, it isn’t just limited to your mailbox list.
The excellent [SOLVED] enterprise I.T. blog has a post on exporting the email list from the shell. Go take a look at it!