Exchange 2007 safe list aggregation
You can give Exchange 2007 a little spam-fighting help by enlisting all the copies of Outlook on your client’s network.
Each time a user rescues a message from the Junk Mail folder, they add it to Outlook’s safe list – and you can bring the contents of these safe lists into Exchange, so they’re used to flag messages as safe well before they arrive on your clients’ desktops.
Exchange’s safe list aggregation feature treats all the safe lists equally – so if any one user has flagged an address as safe, all users will see messages from that address. Safe list aggregation can be resource intensive if you’re working with lots of mailboxes, so work with it when no one’s likely to be using the mail server (though small Exchange installs shouldn’t see much disruption).
To update the safe list data for all the mailboxes in an organisation use the following PowerShell command:
get-mailbox -ResultSize Unlimited | where {$_.RecipientType -eq [Microsoft.Exchange.Data.Directory.Recipient.RecipientType]::UserMailbox } | update-safelist
Safe list aggregation is a manual process. You can automate it, simply by building a script around the PowerShell command and then scheduling it to run at set times using the at command in Windows Server. To schedule a script to run at 1.00 am every day, use the following command:
at 1:00 /every:M,T,W,Th,F,S,Su cmd /c “C:\script.vbs”