The non-delivery report (NDR) is generated when an email message is not able to be sent to the next hop.
Spammers can use NDR as a method to generate spam towards victims by using the victim's email address as the sender. This is called a reverse NDR Att
Microsoft Exchange is a well-known mail, calendar, and groupware program that is used for businesses all around the world.
Exchange allows administrators to achieve better productivity by simplifying tasks such as sending email messages, calendaring, p