If you like!
It's up to you if you want to delete the email record from your Outlook.
Emails are saved as a file copy to the Client Manager system (either through the Outlook Plugin or Webmail).
In saying that, we recommend that you keep these emails within your Outlook as the search functionality within Outlook offers more flexibility than that in Client Manager presently.
If you have any questions, please email our support team at email@example.com