An email message window can be split horizontally into two panes. This enables you to scroll each pane separately so that you can view two sections of a message that you otherwise couldn’t see on the screen at the same time.
You can split messages that you are reading or composing. When reading a message, the message must be opened in its own window. This feature isn’t available in the Reading Pane.
Create a split window
Press Ctrl+Alt+S, and then click where you want the horizontal split.
A horizontal split bar appears in the document window, and the pointer changes to .
Drag the split bar to where you want it. You can scroll the contents in one pane independent of the other pane.
To move or copy text or graphics between parts of a long document, split the message window into two panes. Display the text or graphics that you want to move or copy in one pane, and then display the destination for the text or graphics in the other pane. Finally, select the text or graphics, and then drag the selection across the split bar.
Remove a split window
To return to a single message pane view, drag the split bar to the top or bottom of the window. You can also press Ctrl+Alt+S again to turn off the split view.