If you're installing AfterLogic XMail Server on
Windows 2008 Server or
Windows Vista with
IIS 7, it's important to run the installer from user with "
Administrator" name.
In case of running from a user included to Administrators group, necessary virtual folders in IIS will not be created automatically. That's why it's important to run the installer from "Administrator" user.
Alternatively, you may create virtual folders manually and
this FAQ topic should be useful to you.