Stop sending emails to your customers which contain active links.
Why is this important?
Some years ago Banks and Building Societies pledged to never send emails to customers containing active links. This simple device meant that if a customer received an email with an active link in it, they would know it was a fraudulent email (potential scam, phisher or concealed virus etc) and that they should delete it to remain safe.
Barclaycard have steadfastly refused to do this for their customers.
This is a call to Barclaycard: If you REALLY care about your customers, then STOP SENDING CUSTOMERS EMAILS CONTAINING ACTIVE LINKS.
How it will be delivered