If you want to make the composing window bigger or move it around,

To make it full screen by default, click ... (More options) > Default to full screen at the bottom right.

Also, clicking Compose while pressing Shift or Ctrl may also work for you:

• Shift + Compose: Open in a new window (You can move it around freely.)
• Ctrl + Compose: Open in a new tab (The window will be fixed.)

If you want to compose a reply side by side with the original message,

You can reply in a new window by following the steps below.

1. Click Reply while pressing Shift to open a bigger reply window.
2. At the top right, click the arrow icon while pressing Shift, and you will be able to move the window around.

Q. How can I make KUMail show the title, To, or Cc in a reply by default?

There is no option to change this behavior. If you use the web version of Gmail in basic HTML mode, the title, recipient, Cc, and original message are all visible by default. However, basic HTML mode doesn't support the following feature.

• Chat
• spell check
• any keyboard shortcut
• adding or importing contacts
• changing your sender (From) address
• rich-text format

Thus, we don't support using KUMail in basic HTML mode.