I get regular emails from one source that always show up with unknown date.  According to the KMail FAQ, this is because the sender has created a message where the header has a missing or malformed "Date" field.  I've looked at the header and sure enough the "Date" field is missing.

However, in all other mail programs I've used this sender's emails show up with a date.  The header *does* have a "Delivery-date" field instead of the plain "Date" field.  I believe the other mail programs look for "Delivery-date" if they can't find "Date".  Would it be possible to have KMail do this, too?