This tweak disables the Send and Reply animations displayed when you send a message in Apple Mail.
Start a new Terminal session (in Finder click Applications > Utilities > Terminal).
To enable this setting, type (or copy and paste) the following commands:
defaults write com.apple.Mail DisableReplyAnimations -boolean true
defaults write com.apple.Mail DisableSendAnimations -boolean true
To reset this setting to the default value, type (or copy and paste) the following commands:
defaults delete com.apple.Mail DisableReplyAnimations
defaults delete com.apple.Mail DisableSendAnimations
To activate this tweak please close all instances of Mail, or wait until the next reboot.
Close the Terminal session by typing
exit at the prompt.
Disclaimer: Making any changes to your system can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from these modifications can be resolved. Please follow the instructions carefully and use the information provided at your own risk.