Beginning about 3 or 4 days ago I've noticed a change in the way Gmail groups emails together. It seems to be a subtle algorithm change but it appears that the glue has been watered down a bit. Email messages definitely don’t hang together the way they used to. Now many come In as separate items.
Back when Google introduced the free email service, Gmail, it also introduced a relatively radical shift in the way emails are displayed to the users. There are no folders, instead one can use filters to apply labels to emails which sort of mimics the folder functionality of organizing and categorizing messages. There was also a new approach in displaying emails in that conversations within a thread are grouped together in a thread-like format (much like a forum) and a counter is applied to show the number of messages in a particular group.
It took some getting used to Gmail's way of displaying messages, but I have grown accustomed to it. I don't consider it revolutionary though, it's just different. I'm fine with the traditional way used in Outlook or Yahoo mail. The difference with Gmail, at least at the time it was introduced, was their superior search capability. One could easily recall past messages given a keyword or two.
I'm not sure what the exact grouping algorithm of Gmail is, but I suspect it has to do with the timestamps, senders and receivers, titles and contents of the messages. At any rate, that algorithm has now been tweaked to loosen the condition by which messages are grouped together. This became evident to me a few days ago when I noticed that my inbox suddenly had a large influx of messages. My Gmail inbox receives a number of automated messages that used to be grouped together, perhaps based on their titles. A closer look revealed that those messages that used to clump together, are now presented as separate items.
I assume the change was introduced to make the inbox more usable for most people who were unaware of new messages arriving and getting filed under existing messages with similar titles. In my case it meant adapting to the new methodology and creating new filters to keep my inbox from getting too unwieldy. I suspect many others won't even notice the subtle alteration.