How can I put $group condition to $match?

Question

I have simple aggregate query in mongo:

    collection.aggregate([
        { 
            $match: { owner } 
        }, { 
            $group: { 
                _id: "$email" ,
                count: { $sum: 1 }
            }
        }
    ])

but in the result I need see emails with count great than 3.

How can I do this?