It's not uncommon for us to receive 5+ email replies to a single email thread. Sometimes this happens because multiple senders are sending a response and sometimes a customer might be circling back if they haven't received a reply from us in a quick enough time frame.
The issue with the way that emails route is that those replies are further back in the queue, so when we are several days behind on emails we see the initial email from the customer when there are 5+ email replies already sent and sitting out in the queue waiting for their turn in line.
Within Outlook or other email sources we can use a 'sort by subject' which groups all emails in the thread and only respond to the latest email.
Not having this option or an option that would allow us to see similar functionality in the Contact Center is preventing us from moving more of our email addresses into the Contact Center because that functionality simply won't work for us. (we have 50% of our Support email addresses in the Contact Center right now and we'd like to get to 100% but can't because of this).