[{"_id":NumberLong(301),"telecom":[{"countryCode":{"value":"+1"},"extension":[{"url":"primary","value":["true"]}],"modifiedValue":{"value":"8887778888"},"system":{"value":"email"},"useCode":{"value":"Home Phone"},"value":{"value":"8887778888"}},{"extension":[{"url":"primary","value":["true"]}],"modifiedValue":{"value":"qhammouri@test.com"},"system":{"value":"email"},"useCode":{"value":"work"},"value":{"value":"qhammouri@test.com"}}]}]

db.collection.aggregate([{$match:{telecom:{$elemMatch:{countryCode:{$exists:true},"system.value":"email"}}}},{$unwind:"$telecom"},{$match:{"telecom.countryCode":{$exists:true},"telecom.system.value":"email"}},{$count:"count"}])