In this post, we will create Teams Online Meeting in Outlook using Microsoft Graph API. Before creating a meeting, you should have an access token generated. Refer to my post on How to get Azure Access Token using Postman for Microsoft Graph API.
By selecting the Delete unread copies of this message radio button, mail will get deleted in the recipient's mailbox if the recipient hasn't read it. If you select Delete unread copies and replace with a new message radio button, mail will get deleted in the recipient's mailbox if he hasn't read it and will get replaced by a new message which you can send after clicking the OK button.