If you create an item with Keep history set to 0 (don't keep history), ITEM.VALUE1 doesn't work in the email notification. The email just displays *UNKNOWN*, but if you read the lastvalue of the item in the Zabbix database, you can see the correct value. Why not just use the lastvalue, if there is no history?

This is extremely useful when you have a text item which displays a message when there is a problem, and you don't want to save that message each time, since you cannot use it for trending.