The scenario goes like this. My father has a paid for email address, but being of the older generation, couldn't remember or find where he'd written his incoming and outgoing server addresses. For a quick fix (about two years ago), i configured his outgoing mail server to go through my domain on my hosting plan. Incoming Server = firstname.lastname@example.org Outgoing Server = email@example.com Last week, I migrated my hosted domain to my dedicated server, which has dkim and spf configured. I'd overlooked the fact, that dad was sending via my domain, and it dawned on me today, that he might be having issues. He isn't and can quite easily send emails through my domain. Of course he has the correct logon details, but i thought spf was supposed to stop this from happening ?