Setting up Webmail on plesk control panel
 

Running a couple of Websites via VPS/Plesk 7 control panel and want to set up Webmail for them. BUT can't seem to find the right combination of user name and password to get into any of them (can get to the Webmail log in page) and unable to find exactly where these need to be set / or have already automatically been set.....Anyone point me in the right direction ?