NDR

Vangie Beal
Last Updated June 23, 2021 7:07 am

Short for Non-Delivery Receipt, NDR is an e-mail related acronym. When an e-mail message is composed and sent to an invalid e-mail address the receiving, or in some cases the sending, e-mail server attempts to send an NDR to the sender of the e-mail message, to inform them that the e-mail address used is invalid.

See also hard bounce.