efa-project.org

is there an overview of how EFA works

ie. what order various scanning / rules and filters work

This is so that I can explain to users !!

ie. is it possible to white list a sender such they any type of emails / attachment / content is allowed ?

As EFA is build with MailScanner as its core an good start in reading would be the MailScanner manual, it will probably explain all your questions.

https://s3.amazonaws.com/mailscanner/do ... -guide.pdf

See page 8 for an diagram how mailscanner works with spamassassin