If you want an overview off all the mailboxes in your Exchange 2007 environment with there primairy SMTP address and there extra SMTP aliasses, you can run the following command.
For a overview off all the options after the pipe command, you can the following command.
Get-Mailbox -Identity <useralias> | fl
Get-Mailbox | fl UserPrincipalName, ServerName, PrimarySMTPaddress, Emailaddresses
