In Outlook, when new message arrives an "new items" icon appears in
the right side of the system task bar. Outlook Application object has
an event "NewMail" that corresponds to this.
My question: What is the event in Outlook apllication object or any
other Outlook object that corresponds to the event when this "new
items" icon disapears from task bar. I.e. what event is fired when all
unread items been read.
I need VBA code example. 

I know that there is a Read event when individual item is been read, I
need event when there is no more unread items left.

Ack! :) It's been so long since I've read or marked as read everything
in my inbox... I didn't really know it was possible. Of course, I'm an
email pack rat and I leave things eternally unread rather than delete
them... I know they'll be valuable sometime, right? :)

My guess is there *is* no event when *all* messages are read. I
believe the icon disappears when a) any unread message changes to
"read" (or any message is opened, I suppose...) or b) something gets
moved to, say, Deleted Items box. Which I guess means the question
probably can't be answered as asked.

Obviously you know there is a Read event. That's what hides the icon.
All messages read, now that's an action to do every time a message is
"read" and would probably involve counting the number of messages and
subtracting unread. If it's zero, then you have your secondary event.

I suppose you'd probably have to qualify and determine if you want to
count all messages in all folders, or just Inbox...

This is a free comment. Want some peanuts?

I thought about it. I?ve seen people doing something like this and
running in all sorts of troubles. For example, user could not open
message while macro was scanning the whole list. I've also seen some
users are keeping thousands of messages in their Inboxes. So going
over them all every time user opens one of the new mails is just plain
impractical. Somehow I do not think that is what Outlook is doing. It
can be optimized, of course. May be there is a way to order messages
in box by read/unread flag or somehow create filter for unread only.
Unless nothing else will surface that is what I'm planning to do.