In my next few posts, I plan to write a series on Sender Authentication, specifically on SPF and a little bit on SenderID and possibly even DomainKeys.
To my more technically oriented readers, I apologize if this is familiar territory for you as I hate to bore you. However, I do have other readers that are not quite as familiar with these methods and would like to get a basic understanding of them. In addition, because of the shift in the industry to tend towards sender-authentication, I think it makes sense to write about it. After all, nothing grounds your knowledge in a subject better than teaching it.
My plan is to go over the basics of email headers, email envelopes and SPF records. Then, I will go over how SFP and SenderID attempt to identify illegitimate senders using these records and how spam filters can use them to their advantage.
There are quite a number of resources on the web that already deal with the subject. I have read a lot of them in order to get my own understanding up to speed. I plan to do my best to provide a nice overview of the entire subject.