In Outlook 2019, when a message is deleted it should either:
- Move to Deleted Items, or
- Be removed from view but still exist, if a view filter is hiding it.
From the available information, the most relevant documented cause for “disappearing” items is that a filter is applied to the folder view so the items are not actually visible, even though they still exist.
To check whether a filter is hiding deleted or other messages in Outlook 2019:
- Open Outlook and go to the folder where messages seem to disappear (for example, Inbox or Deleted Items).
- On the ribbon, select the View tab.
- In the Current View section, select View Settings.
- Select Filter.
- Go through each tab in the Filter dialog:
- Tasks
- More Choices
- Advanced
and look for any conditions that could exclude messages (for example, only showing unread items, certain dates, senders, or sizes).
- Remove or adjust any filters so that no conditions are hiding messages, then select OK, and OK again to close the View Settings.
After clearing filters, check the folder again. If the items were only hidden by the view configuration, they should now appear.
If items were actually deleted from Deleted Items, recovery depends on the mailbox type and retention settings. In that case, use the “Recover items deleted from this folder” option (where available) described in the Outlook deleted-items recovery article to restore messages that were removed from Deleted Items.
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