From the Lotus Notes Help
<b>To work with messages in the Trash folder</b>
Messages appear in the Trash folder until they are <i>permanently</i> deleted. You can remove them from the Trash folder and restore them to the view or folder from which they were originally deleted. You can also permanently delete selected messages or all messages.
1. In the navigation pane, click the Trash icon.
2. (Optional) If you want to work with only some of the messages, select them.
3. Do one of the following:
To remove the selected messages from the Trash folder and restore them to view or folder you deleted them from, click Restore.
To restore all messages in the view, click “Restore All.”
To permanently delete the selected messages, click “Delete Selected Item” and select Yes in the message that appears.
<b>To permanently delete all messages in the view, click “Empty Trash” and select Yes in the message that appears.</b>
As you can see emptying the trash deletes the mail completely there is no more <i>soft deletes</i> after this. By default the database properties on soft deletes will permanently delete mail 48hours after their deletion. This is changed via the Advance tab of the database properties.
If you need these back then the only way would be to recover them via resend or system restore.