Group by subject
To navigate your emails easily, you can enable the 
→ Group messages by threads option. Your emails will be grouped into message threads. To expand or collapse a list of messages in a thread, click the subject of the message. To view an email in a thread, click on the line that contains this email.
What you can do with email threads
Emails are grouped as a thread when:
- They have the same recipients, senders, or subject.
- They contain a header with the same ID.
Emails can be grouped in the same thread even if some of them are in different folders.
Note
Note that the messages stored in the Spam, Deleted and Drafts folders are never grouped.
You can also move within a message thread by using the message page.
To ungroup messages, disable the → Group messages by threads option.
What you can do with emails inside threads
Warning
Messages can be managed within a thread if you enable the open message in list of messages option.
You can manage all emails in a thread together (for example, mark all as read, delete or forward them all). To do this, click 
in the email menu.
