Gmail will warn you when responding to emails sent from outside of our domain (@umd.edu) and not in your contacts. This feature can give protection against forged email messages, impersonation, as well as common user-error when sending mail to the wrong contacts.

Image Courtesy of Google

How does it work?

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