Many of the risks posed by e-mail are quite obvious to the user, there can be very few users unaware of the risks of 'phishing', and there forever seems to be news articles about celebrities that have had their e-mail accounts 'hacked'. There are however a number of risks that are not so apparent - e-mails can be intercepted or even 'spoofed'. In fact in many mail clients it is trivial to make it look like an e-mail has originated from another persons e-mail account, whilst the more savvy users may check the original headers, many users would not think to do this, let alone know how to view them (In fact the more recent versions of Outlook don't allow you to do so.)

So why would someone 'spoof' an e-mail from you? Aside from phishing there are many other benefits - I could for example, pretend to be one of your old friends in order to get your home address, or as a prospective employer in order to get your social security or National Insurance number. There are many other uses that such an attack could be used for, however the actual likelihood of such an attack is reasonably small as most e-mail attacks are generally sent out 'en masse'.

How many times have you signed up to something on the net, only to be asked to re-confirm some security details by e-mail? Did you send the details back? Most people would, but that e-mail could have been intercepted somewhere along the journey - unlike sending details through the post, emails can be read and copied wihtout leaving a trace of evidence. If you are planning to send personal details via e-mail, make sure you encrypt it first. If the recipient doesn't have the means to provide you with an encryption key, ask them if you can provide the details in a different format (phone, mail etc.).