[Kushan]

So, from what I understand (Correct if I am wrong), Virgin's new filtering service is VERY picky about the SPF record used by the sending email server. It seems if no SPF record exists (or is invalid), it always goes to spam. Unfortunately it's easy to set up an SPF record if you own the domain so it's not difficult for spammers to make use of that (or just use stolen hotmail/gmail/yahoo accounts, which will have correct SPF).