Apple lets you thread messages on your iPhone, or have Mail automatically group related missives. The beauty of this arrangement is that you can easily trace back an e-mail conversation.

1

When you organize messages by a thread, the related messages show up as a single entry in the mailbox, with a number next to the right-pointing arrow in the entry indicating how many underlying messages are represented by the thread.

So the number 6 next to Robert's message (left) shows that six messages constitute this particular thread; when you tap that listing, the six threaded messages appear, as shown on the right.

2

You have to turn on threading in Settings. From the Home screen, tap Settings→Mail, Contacts, Calendars→Organize by Thread.

Finally, tap the button so that it reads On. You may have to scroll down to see the Organize by Thread setting.

3

When you look at a message that’s part of a thread, the numbers at the top of the screen tell you your location in the conversation.

For example, the message is number 1 of 6 in this thread.