Just do remember to back up the registry for restoration before modifying it in case problem occurs.įurthermore, if the issue is not with the modified date, please double confirm that the correct folder is selected under the 'Archive this folder and all subfolders' option. Once confirmed that the issue is due to the Modified date, you can follow the suggestions shared by Manu to add the 'ArchiveIgnoreLastModifiedTime' registry. You may click on the Column titile 'Modified' to sort the messages based on the modified date and time.Add the Modified Column by clicking View Settings > Columns, select 'Date/Time fields' > Modified, click Add to add it to the view:.

Switch to the Preview view by clicking View > Change View > Preview.To verify this, you can view the modified date using the steps below: So agree with Manu that the issue could be related to the modified date of the old messages. By default, Outlook archives Email messages based on the received date or the last modified date and time, whichever is later, see this KB article.

Outlook 365 cleanup tool