Phishing is a common method to get access to, for example, user credentials, data or money. 

To prevent this, JU uses an anti-phishing policy that compares incoming e-mail with the history of messages and flag if the sender's name matches a previous conversation, but that the e-mail address itself is not the same.

In this document you can read more about anti-phishing policy and see examples. Pdf, 135 kB.