Chip: > Okay I guess it does. Meaning there are no standards for the way > emailers should respond to bounces?
According to RFC 5321, the definition of the Internet email protocol,
an undeliverable email message is returned to its MAIL FROM address,
and that return message is sent with the null MAIL FROM adress.
Undeliverable mail with the null MAIL FROM address is not returned.
That answers your question, but you probably meant something else.
Wietse
