It is impossible to activate SmarterMail Server in the Plesk Control Panel.
The following error can be found in the Plesk Event Viewer:
Can't obtain domains list.
Failed to log in.
at (VPackageManager::setDefault line 370)
at execute console command --set(vconsoleapp::start
at execute "C:\Program
"--default=smartermail"(vconsoleapp::run line 140) Execute file name: C:\Program Files\Parallels\Plesk\admin\bin\defpackagemng.exe
CauseMost likely there are no any clients and domains created in Plesk. SmarterMail requires at least one domain to be created.
To activate SmarterMail it is necessary to create at least one Client and one domain in Plesk Control Panel. Once they are created please try to activate SmarterMail again.