Group by subject
If you frequently correspond with a certain person/people, turn on the option (to the right above the list of messages). Your emails will be grouped by email thread. To expand or collapse a list of messages in a thread, click the subject of the message.
The message thread displays all emails grouped by a selected subject, even if they have different recipients or senders, or are in different folders. Messages are only grouped by subject. Senders and recipients do not factor into grouping.
Note. Note that the messages stored in the Spam, Trash and Drafts folders are never grouped.
You can also move within a message thread by using the message page.
To ungroup messages, disable the option (above the message list, on the right).
