Click "My Services" in the left menu bar.
Now select "View Technical Details" within the "General" tab.
You should see a list of your Zen services. Find the service with your Zen username and click "Select".
You'll see a table of information, look for the heading "Email Settings".
Your "Email Address" will be displayed on this screen. It's important to note to include the full address including the "@zen.co.uk"" part.
By clicking on "Password", it will show the password assigned to your email account.