What color bubble indicates that an e-mail in thread views is NON-inclusive or a duplicate?

The gray bubble in thread views indicates that an email is non-inclusive or a duplicate. This color coding helps users quickly identify the status of each email within a thread. When an email appears with a gray bubble, it signifies that the email does not contain new or relevant information, either because it repeats content already present in the thread or because it was sent to a different group of recipients who are not currently part of the conversation. This feature is particularly useful in managing email threads for clarity, enabling users to focus on the most pertinent communications without getting sidetracked by repeated messages or irrelevant duplicates.