From Exchange 2007 it's possible get a text file with all SMTP email for every user/Distribution list.
You can get this information with powershell.
Here is the complete command:
Get-Recipient -Resultsize Unlimited | Select RecipientType, Name -Expand
emailaddresses | Select Name, SmtpAddress, RecipientType | Sort Name |
Format-Table -AutoSize > EmailsList.txt
[original article http://blogs.sysadmin.it/ermannog/archive/2013/09/10/elenco-indirizzi-smtp-in-exchange-con-powershell.aspx]
