You need to load the ORF Log Viewer, load the logs then click on View, Filter, Add Rule, Select "Sender", In the Email Address/Mask box enter "*@alliance-leicester.co.uk" (no quote marks) and then Add another Rule and Select "Filtering Point" then select "On Arrival" and click OK twice.
Press F6 to see the preview Panel and then select a line that will hopefully be displayed. In the Preview Panel, it should hopefully tell you the user account that was used.