When you use the Email Experience Manager in multisite environments, you must differentiate between the sites and their manager roots. A manager root contains all the settings that control the user experience of the module. You can create additional manager roots manually.
By default, the module searches for the manager root under the item defined in the Default Root Parent setting of the /sitecore/system/Modules/E-mail Campaign Manager item.
The location of the manager roots is defined in the /sitecore/system/Modules/E-mail Campaign Manager/System/Root List item. The module updates this item automatically.
In a multisite solution, the manager roots that relate to different sites can be located in different places in the content tree.
A user can have access to several manager roots. You can use standard Sitecore security applications to grant users permissions to specific manager roots.