Collapse messages to be easier to read

Some email message threads can get to be extremely long. Additionally, sometimes, each message will include all previous message data at the bottom (which is supposed to be hidden, but often isn’t), so the messages themselves can be extremely long. Because of these issues, it would be great to be able to “close” or “collapse” a message to make it easier to read and review long strings of messages. Gmail, for example, will display all the previous emails as collapsed and you open them to view the whole message. This is sooooooo much easier to navigate.