Disable/enable separate aliases

I've created a couple of mail aliases, but I don't want to use them all the time. Would be great if you could select for each alias if it's enabled or disabled. Disabled aliases won't receive any mail, so this also reduces spam. And you're sure that you can use the same alias again once you need it by just enabling it (if you delete it and want to register it again later on, it might be taken in the mean time)