how do i change email alias on all exchange 2000 users to their email adress or user logon name?

Do you want to change their SMTP address to match their current alias, or their Exchange Alias to match their current SMTP address?

Changing their email address to match to match their alias (the former) is easy, create/modify a recipient policy and apply it.

The later is a bit harder to do, as it would require you script out/in (think ldif); a good deal more work and testing is required to ensure you dont break anything with this kind of change.  This is much easier in Exchange 2007 since you can do it with Powershell, but doesnt do you much good if you're on Exchange 2000.

Erik

hi,

i have a exchange 2007 up and running and i can see all the old users, can i use powershell from the exchange 2007 then?

i want the alias to either match email address or the logon name.

You can also use ADModify .NET to change properties and attributes on ad objects

thanks, loooks like a great tool. still i cannot se any field to change the mailnickname field.

great, setting the alias in the Exchange Management Shell is easy and will work for your legacy Exchange (2000) users:
set-mailbox -identity oldalias -alias newalias

You're going to want to play around AND TEST before pulling the trigger in your environment, however you could set the alias for all users to their SamAccountName (as an example, if you wanted to make it more complex you could use other attributes such as UPN) with the following:
Get-Mailbox | ForEach-Object { Get-User $_ | Set-Mailbox -Alias $_.SamAccountName }

Have fun,
Erik

thanks this worked for me:) but when running this command i get this after i ran it

WARNING: By default only the first 1000 items are returned. To change the
number of items returned, specify the parameter "-ResultSize". To return all
items specify "-ResultSize Unlimited" (Note: Returning all items may take a
very long time and consume a large amount of memory depending on the actual
number of items). It is not recommended to store the results in a variable;
instead pipe the results to another task or script to perform batch changes.

where do i but -resultsize unlimited in this code: Get-Mailbox | ForEach-Object { Get-User $_ | Set-Mailbox -Alias $_.SamAccountName }