qconfirm-check-mid is run by
before requesting a delivery confirmation for mail from an envelope sender
qconfirm-check-mid exits 0,
doesnt request a delivery confirmation from this sender.
qconfirm-check-mid assumes the environment variable
SENDER to be set to the envelope sender mail address, and expects a mail message
on standard input.
qconfirm-check-mid reads the headers of the message available on standard input, and checks for
each In-Reply-To and References header if it contains a Message-ID
that matches one of the space-separated
QCONFIRM_MID if set, or one of the
mids given at the command line, and exits 0 if so.
A header is successfully matched against
mid if the header field contains the string
mid>, case distinctions are ignored.
qconfirm-check-mid is called
this References header is matched successfully:
References: <email@example.com> <some@thing>