Composing Window splitter above attachments is fixed height, not adjustable

Composing Window splitter above attachments is fixed height, not adjustable

When adding attachments to an email, the window becomes split, and the attachments appear in a very small separate window at the bottom, suitable for just a few attachments, depending upon your window resolution. If you add more than 4-6 attachments, a scroll bar appears, but the window splitter doesn't expand, nor can I adjust the window splitter manually. The attachment area is tiny, as is the scroll bar. Have you considered re-designing that function?