Delivered-To:
Mark a mailing list expansion qmail
The qmail program uses a Delivered-To:
header to
trace all the alias and mailing list expansions
through which an email message passes. This is
similar to the way Received:
headers are used to trace
machine hops. When qmail
expands a mailing list, it adds a Delivered-To:
header to
the top of the message:
Delivered-To: list@host
If an identical header is already present,
qmail bounces the message.
This prevents several kinds of mail loops. (Note
that the SmartList program
supports an X-Loop:
header with the same
function.)
The Delivered-To:
header should never be declared in the configuration
file.
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