Targeted auto-response messaging

The techniques disclosed herein improve existing communication systems by automatically generating auto-response notices when a message to a user is related to a group with which the user is no longer a member. For example, after changing groups within a company, the user may still receive numerous messages related to the former group. Messages intended for this user may then be identified as related to a group with which the user is no longer associated based on the identity of the sender, other recipients of the message, the contents of the message, and a message context. The system may present an auto-response notice to the sender while the message is being drafted and before it has been sent. The auto-response notice alerts the sender of the changed group affiliation of the user.