The order that items are retrieved from the queue is separate from replying to emails. The queue is designed with First In First Out. Without seeing the collection you're adding to the queue or the design of the process that is retrieving from the queue, I can't really guess why it would be happening in the wrong order.
I'm not sure what you mean by 'add each item one by one into collection then it will take time'. It would be slower, but unless you're adding thousands of items at once, you are unlikely to notice the performance difference from Control Room.
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Dave Morris
3Ci @ Southern Company
Atlanta, GA
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Dave Morris, 3Ci at Southern Company