Sender Policy Framework (SPF) is an open standard that aims to help prevent spam, and stop legitimate email from being tagged as such. While the specifications can take some time to understand, there are some web-based tools to help you make creating your SPF records a little easier than by hand, but I still find them to be a bit misleading. According to the SPF FAQ the simplest way to create your SPF record is to simply list the IP addresses of all servers that mail goes out through, e.g.:

Here's a wonderful explanation of why Microsoft's "open" OpenXML "standard" is a wolf in sheep's clothing: http://www.robweir.com/blog/2006/01/how-to-hire-guillaume-portes.html In short, the specification is littered with little tidbits which say that to properly display a file you must understand details of how 12 year old software (Word 95) worked, or reverse engineer it.... And that, folks, is why I don't use Microsoft software and stopped buying their junk several years ago. Update: Just to better explain why this is a problem, there is no guarantee that Microsoft is using its own specifications in its own software, namely Office 2007.