no option to ignore previously reported new mail

If I use cgmail to check a gmail account that happens to have several unread messages in it, all of these unread messages show up every time a new message is received. It would be useful if there were an option to ignore previously reported new mail. It might work like so:

- start the cgmailserver, and it shows N unread messages in the account.
- click on the tray-icon to 'ignore the current new messages' and hide the icon. (this click-behavior would need to be something the user can configure in the preferences)
- the next time additional new messages are received by the account, only these newly received messages are displayed in the notification balloon (and not the messages which are being ignored), and the notification icon reappears in the tray.

Of course a natural question might be: why would one have a bunch of unread email in his/her account? The answer is because sometimes one might have received lots of mail, and not had time yet to go through it all. To notify that all of this unread mail exists every time a new message arrives is a bit too much visual noise.