The email related to HMRC and I have read that BT are blanket rejecting any emails with HMRC in the message subject - short sighted really as I am the Treasurer for a small charity and regularly send out emals of this nature.
A clear document explaining what is permissable in emails (i.e. a list of "bad" words) would have been helpful. Or simply somewhere to find out what BTs policy is that has been violated.
I wasn't sending bulk mails so the link isn't helpful in the slightest.