You can. You can turn off new messages zooming onto the screen as you start composing in Mac OS X Mail, and you can prevent their sliding out towards the top, too.
Disable Window Animations in Mac OS X Mail
To turn off animations when you start a reply and send a message in Mac OS X Mail:
- Quit Mac OS X Mail.
- Open Terminal.
- To disable the zooming animation when you start a reply:
- Type "defaults write com.apple.Mail DisableReplyAnimations -bool true" (not including the quotation marks).
- Press Enter.
- To disable the sliding animation when you send a message:
- Type "defaults write com.apple.Mail DisableSendAnimations -bool true" (without the quotation marks).
- Press Enter.
- To disable the general Mac OS X zooming animation when you open a new window (say, to compose an email in Mac OS X Mail):
- Type "defaults write NSGlobalDomain NSAutomaticWindowAnimationsEnabled -bool false" (without, again, the quotation marks).
- Press Enter.
Note that these settings will not disable the sliding animation you see in full-screen Mac OS X Mail.

