Hello! I have an SBS 2003 SP1 server as my only email server. I want to set up SPF records. Per this article [URL]http://support.microsoft.com/?id=912716[/URL], the recommended SPF record is as simple as this example. v=spf1 mx -all However, creating an SPF record from the Microsoft web site at [URL]http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/default.aspx[/URL] comes up with a much more detailed SPF record, such as v=spf1 ptr ip4:67.x.x.x mx:mail.mydomain.net -all My current SPF is published in my public DNS as follows: v=spf1 mx:mydomain.net -all I recently started getting emails into the IMF that claim to be from my domain but are not. I have not enabled Sender ID yet. In order to prevent these emails from being accepted, is my only other step just the implementation of Sender ID filtering? Thank you for helping! Gregg Hill