It is very frustrating when trying to launch Developer Tools for Chrome and accidentally using "the other" common Command+Shift+* command key combination (instead of Command+Option+I) and having Mail.app launch instead... So, better to just remove the other shortcut ;)
The thrust of the above article is reposted here:
defaults write com.google.Chrome NSUserKeyEquivalents -dict-add 'Email Page Location' '\0'
defaults write com.google.Chrome.canary NSUserKeyEquivalents -dict-add 'Email Page Location' '\0'
defaults write com.apple.Safari NSUserKeyEquivalents -dict-add 'Email Link to This Page' '\0' 'Email This Page' '\0'