By default, admin can log into WebMail Lite admin interface at
/adminpanel/ using superadmin login and empty password. Upon logging in, it's possible to change admin password, as well as admin login username if necessary. Admin credentials can be reset as shown here.
If you wish to restrict admin access so that it can only be available from one or several IP addresses, that's done by editing
data/settings/modules/AdminAuth.config.json configuration file:
AdminAuth.config.json file is missing under
data/settings/modules directory, be sure to click "Update configuration" button in Database Settings screen of admin interface.
You can supply the list of IP addresses under SuperadminWhitelistIp parameter, for example:
and if the array is empty, that means all the restrictions are lifted.
If you need to disable admin access entirely, you can set Disabled to true in
data/settings/modules/AdminAuth.config.json file. You'll still be able to edit configuration files directly, of course, this is only about blocking WebMail Lite admin access via web.
The same effect can be achieved by setting AdminLogin to an empty string in main in
data/settings/config.json configuration file.
In version 9, logging into admin interface from main login page is not allowed, and old adminpanel web client which was used in v8 is now disabled. You can enable it by setting "AllowLoginFromCoreModule" to true in
data/settings/modules/AdminAuth.config.json configuration file.