Postfix header check to reject certain senders

[Gareth]

A bit off topic but you are normally a friendly bunch :)

I am trying to get postfix () to reject mail from certain senders rather
than accept and then delete it in mailscanner.

One such mail has the following in the headers:-
From: root at adsl.linguaphone.com
To: root at adsl.linguaphone.com
Subject: adsl.linguaphone.com security run output

I have my postfix header checks set to use regexp matching and the file
contains :-

/^From:.*\@adsl\.linguaphone\,com/                      REJECT Sender
address blacklisted.
/^Received:/ HOLD

The problem is that the mail I am trying to block is not being rejected.
All mail is being put in the hold queue and Mailscanner working
correctly so header checks are working.
Have I done something wrong with the syntax?