I am having some problems when the users access some pages that has the "send this article to a friend" resource, because the message arrives with the senderīs address that is filled in the page and not with a specific account.
So its impossible to set the address as a white-listed.
Are you sure? Look at the Return-Path header..
That much should always be the same, or at least the same domain. SA treats Return-Path as an alternative to From:, among some other headers, and will check all resulting addresses against whitelist_from and whitelist_from_rcvd rules.
