How to use Prevent Reply All

THIS ADD-IN IS RETIRED AND NO LONGER SUPPORTED

Unintentional clicking Reply All for a multi-recipient message can be really annoying especially when the email was addressed to hundreds of recipients from a distribution list. If you want to avoid sending an email to all initial recipients by accident, just use the Prevent Reply All utility of Add-ins Collection for Outlook.
You'll get a warning message each time you hit Reply All:

To switch on the Reply All alert, just click Prevent Reply All on the AbleBits tab in the ribbon:

To turn the option off, click the button again.

Also, you can use the Alert Reply All to check if there are several recipients and get a warning in case you forget to include them all in response to a group email.