Toolkit
Story: Notification emails cause virus-like chaos
On the one hand side, yes, the vast majority of virus emails have a spoofed sender address, hence, the notification will be send to an innocent third person, which will probably rather consider the email as spam than as a helpful hint.
On the other hand, by providing email relay and delivery to customers, the service provider is in charge for email handling. Senders must be informed if - for any reason -an email is not delivered to the recipient, which for security resons is usually the case if a virus was detected. In other words, if I send an email to a person with an attachment containing a virus and this particular email is deleted by an automatic virus scanner, I expect to be informed about the non-delivery of my email, don't I?
Full Talkback thread



