Google has released a new Gmail security feature will warn you when responding to email addresses from outside of our domain ( and not in your contacts. This feature can give protection against forged email messages and impersonation, as well as common user error when sending mail to the wrong contacts.

How does it work?

  • When a you hit reply in Gmail, Google scans the recipient list, including addresses in CC and BCC. If a recipient is both external to our organization (i.e., doesn't have an and not present in your Contacts, Gmail will display the warning.
  • If the recipient is intended, you can dismiss the warning and proceed with the response. Gmail won’t show the warning again for that recipient.
  • This change also affects TERPmail - if you hit reply from a TERPmail account and a recipient doesn't have an account (and isn't in your contacts), Gmail will display the warning.