You will appreciate the Alert Reply All feature if you often hit Reply when you should hit Reply all in Outlook. The utility can check if there are several recipients and you will get the Reply All warning in case you forget to include them all in response to a group email:
To enable the Reply All alert, just press the Alert to Reply All button on the AbleBits tab in the ribbon:
To turn the option off, click the button again.
Also, you can use the Prevent Reply All utility to avoid sending an email to all initial recipients by accident.