'Could not analyze message'

[Nigel Kendrick]

Yesterday and today we have had four very short, legitimate, plain text
emails (not at the same time) from the same sender that were quarantined as
'Could not analyze message'. I have had a look at them and cannot see any
formatting errors or suspect content so I just wondered what might have
triggered such an event.

Is there anything I should perhaps check?

Thanks

Nigel Kendrick