Messages in an e-mail thread are automatically moved to the Deleted Items folder

When you use the Ignore feature in Microsoft Outlook 2010 or later versions, messages are automatically moved to the Deleted Items folder.

To resolve this problem, remove the Ignore status of the e-mail thread. To do this, follow these steps:
 

1. Select the Deleted Items folder.
2. Select the message that is currently set to be ignored by Outlook.
3. On the Home tab on the ribbon, click Ignore in the Delete section.

4. Outlook 2016
   Outlook 2013
   Outlook 2010

5. If you are prompted, click Stop Ignoring Conversation.

At this point, the message is automatically moved from your Deleted Items folder to the folder from which the message originated. Future messages for this thread will not be automatically deleted.