I know of no fix to make it open maximised. This is a common request.
But you often can TRAIN IT to open larger. Click to create that window. Resize it (do not maximise it!) and then close it (top-right-X). Repeat if needed.
Bob
I'm running OE 6 on Win 98 2nd ed. Every time I click on 'new message' or a 'sent' message, the window that opens is minimised and I can't find any way to have it open maximised. I know someone will be able to help....![]()
David

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic