On Windows Hosting
If you have Webmail enabled in Parallels Plesk Panel, you can access your email at:
http://webmail.yourwebsitename.com
Where "yourwebsitename.com" is the name of your domain.
Sign into your account using the user name and password you set up in Plesk or provided to you by your administrator. user name is going to be your email address in [email protected] format.