How to delete connected mailboxes?

Question

Active Directory

There are several more mailboxes connected to the user account in AD in the mail, I would like to delete them, but they are not deleted, with a standard deletion from Outlook, an error occurs:

Эта группа папок связана с учетной записью электронной почты. Чтобы удалить учетную запись, перейдите на вкладку "Файл", на вкладке "Сведения" нажмите кнопку "Настройка учетных записей", выберите учетную запись электронной почты и нажмите кнопку "Удалить"

Answer 1

Well most likely they were connected through Exchange. Turn it off through it.