When you try to change an email id password from a subscription (for example yourdomain.com) you may receive an error:
Error: The user account was not found. This could happen if the user account was removed by someone else while you were changing its settings.
Login to your Server via RDP
Open Command Prompt
Login to MySQL Database (usually in %Plesk_admin%\MySQL\bin)
Run the following command:
UPDATE smb_users SET ownerId=(SELECT id FROM clients WHERE login='yourdomain.com')WHERE email like '%yourdomain.com';
Don’t forget to replace “yourdomain.com” with your actual domain name.
All email accounts now properly show up under their clients and can changed their password through Plesk.