SMG scanned an email with Microsoft Excel as its attachment, which resulted in Unknown URL verdict. However, there was no URL present in the mail nor in the spreadsheet.
Excel’s automatic hyperlink feature (enabled by default in AutoCorrect option) interpreted a home address as a hyperlink.
For instance, Excel's automatic hyperlink feature interpreted a home address "H.No 111 Sample Drive Anytown SomeCountry" to be "http://h.no/".
The issue is not with SMG. It works as expected when it scans the attachment for any URL as per normal process, which in this case, found the hyperlink supplied by Excel.