Sample of "CHANGES REPORT"
When you receive the 2nd and subsequent reports, the CHANGES since the last UPDATE appear in the body of your email like this...
WAS = a price change (reduction or increase)
NEW = a new listing, but it also could be a "re-issued" listing. (see REMOVED)
REMOVED = sold/canceled/withdrawn; in the latter case, may show up as NEW
 
This saves you a lot of time, since you will already be familiar with those listings that have <no change> next to them.
 
Every subsequent email will have all "Active" Listings attached to the email.
 
You simply over-write the previous attached email files I sent you before.