What messages are included when I reply or forward in Gmail?

To understand what messages are included when you reply or forward in Gmail, you first need to understand quoted text. In Gmail, you will see a small "show quoted text" link at the bottom of some messages (see image below). You may not have realized it, but as in Outlook, Gmail lists all previous messages below the new message. When you click "show quoted text," you can see all of the previous messages. Gmail doesn't want you to have to see the same message over and over, so any messages you've already received are hidden in "show quoted text."

Now, each message in a conversation has its own "reply" and "forward" links. When you use these links, Gmail includes the current message along with any messages in "show quoted text." However, you still have complete control over what you are sending. After you click the reply or forward link, Gmail gives you a scroll box to enter your new message - the previous messages are also listed in the same scroll box. Your recipient will only receive the information in the scroll box. From here it is works the same way it did in Outlook - simply delete any information that you don't want to send.