Scope   In this article I am setting this up on a Windows 2008 (64-bit) domain controller to sync Active Directory user accounts with Google\Postini hosted mail security. Although the download site doesn’t list Windows 2008 as a supported operating system it does work but there is an additional step to get this setup (step [...]

Enter the below into the DNS SPF record for a domain using postini v=spf1 a mx ip4:X.X.X.X include:spf.postini.com Where X.X.X.X = the IP of the sending server.

Create a “postini archive” contact and give it the postini archive email address (which you can get from the archive settings at the user-level org in postini). Specify this address as the journalling recipient on the mailbox store. Hide the “postini archive” account from the the exchange address list.