ALTHOUGH Microsoft"s anti-spam sender-ID is disliked by Open Sources, it is providing popular with the very people it is targeted against. According to E-mail security outfit MX Logic, spammers are taking to sender-id faster than an IT journalist to whisky. The science is pretty easy. Under the Sender Policy Framework (SPF), companies publish a list of authorised E-mail servers for the domains they control. This is used by those receiving E-mail to make sure the purported server of origin matches the one listed in the message header.