I'm on macbook pro and osx and the minimize option when composing emails gone!

Yesterday, a few looks things changed on my macbook pro - I suppose I could have had an upgrade or fix or something, I didn't do anything specific that I can recall.

When composing an email, the email no longer shows the minimize buttons in upper left hand (or red or green for that matter) and minimize is also greyed out in the menu as an option, my only choices are delete and send to get out of the email. This won't do!

Thank You.