Safelist aggregation in Microsoft Exchange Server 2007 refers to a set of anti-spam functionality. This functionality is shared across Microsoft Office Outlook (Junk E-mail Options in Outlook 2007) and Exchange with Edge Transport server role. You should schedule periodic updates of safelist aggregation to make sure that the most up-to-date safelist aggregation information is in the Active Directory directory service.

Steps to configure safelist aggregation

1. Logon to the Exchange 2007 server that has Edge server role installed.

2. Use the Exchange Management Shell to enable content filtering. Type the following cmdlet:

   Set-ContentFilterConfig -Enabled $true

3. Logon to the Exchange 2007 server that has Mailbox server role installed.

4. Create a batch file (e.g. “Exchange-UpdateSafelist.bat”) with the following code:

   “d:\Program Files\Microsoft Command Shell\v1.0\Powershell.exe” -psconsolefile “d:\Program Files\Microsoft\Exchange Server\bin\exshell.psc1″ -command “get-mailbox | where {$_.RecipientType -eq [Microsoft.Exchange.Data.Directory.Recipient.RecipientType]::UserMailbox } | update-safelist”
   

   When you use the Update-Safelist cmdlet, the default value for the Type parameter is SafeSenders. You can specify the value of this parameter: the Safe Senders List or the Safe Recipients List, or both. For more information see the following Microsoft article: “Update-SafeList” – http://technet.microsoft.com/en-us/library/bb125034.aspx.

5. Schedule updates of safelist aggregation. Use the Windows Scheduler or the Exchange Management Shell and type the following command:

   at 2:00 /every:M,T,W,Th,F,S,Su cmd /c “D:\Scripts\Exchange-UpdateSafelist.bat”

Useful links:

• “Safelist Aggregation” cmdlet on Microsoft Technet: http://technet.microsoft.com/en-us/library/bb125168.aspx
• “How To Use the AT Command to Schedule Tasks” on Microsoft Technet: http://support.microsoft.com/kb/313565/en-us