Mountain Lions new Mail VIP feature is among my favorite improvements of the update; it gives me just the right amount of control over notifications and filtering to make sure I see what I need to and dont get overwhelmed by an email deluge. But shortly after upgrading I noticed a peculiarity: Sometimes, Mountain Lion would pop up two notifications for the same messagethe first segueing directly into a second.

I realize that these contacts are Very Importantafter all, thats the way I marked them. But I couldnt help but think that one notification of their email would still be plenty, no matter their importance.

I let it go for a while, hoping it would work itself out, but after several months my patience wore thin. After doing some research, I discovered that Mail and Mountain Lion arent the only culprits here, though they have their parts to play.

The account giving me trouble belongs to Gmail and is set up via IMAP (one of the two major mail protocols, and these days the more common one). Gmail offers the ability to synchronize your labels to folders on your local client via IMAP. This means that the same message can end up being delivered to multiple folders; to Mountain Lion and Mail, its as if youve received multiple copies of the same message, hence the multiple notification triggers.

In my case, the root of the trouble was Gmails Important label. Its part of the services Priority Inbox feature, which is supposed to identify which messages need your attention first. (I suppose you could argue that it worked, just a bit too well.)

The fix, as it turns out, is pretty easy, and I owe it to a post on Apples discussion forums. Visit your Gmail account on the web, open up Settings, click on Labels, and uncheck Show in IMAP for Important and, if you havent already, for All Mail. (If you still see double messages after that, you might need to uncheck other labels as well.)

If all goes well, you should be down to a single VIP notification per messagejust the way Mountain Lion intended.