Sorry of course, you are right. As long as my mail server is mail.whatever and it responds as mail.whatever then it can host emails for various domains and I don't suppose the people whose website I am hosting would care if it was mail.hostingcompany or mail.theircompany as long as they can send and receive.
I can see why it is an indicator of the authenticity of a mail server but to take the view that any server that is called john but responds as julie should be totally blocked is a little hard-line. Perhaps it could be ranked as a little suspect but not as irrefutable spam that must be stopped from reaching Virgin Media users' inboxes at all costs.
Then, if combined with other factors, such as John wanting to give me all his cash, recount lorem ipsum to me or sell me some pills then perhaps these factors together could lead to the email being totally blocked whereas otherwise the spam scoring would be added to enable the email client to decide if John is also Julie, or if that only applies at the weekend!
At least that way John could be whitelisted to be Julie when he wanted to be as the recipient would then know that was how he rolled and he wasn't an evil spammer, just a little questionable.
