davecb@nexus.yorku.ca (David Collier-Brown) (06/07/91)
I hate to say ``I told you so'' (:-)), but this can be reduced to a solved
problem in mail transport...
Consider the recent discussion of the Zmailer behavior on encountering an
unparsable/illegal header line: after extensive error analysis, the author
chose to replace the header with a legal header which merely reported the
problem.
Another mailer (on VM?) does substantially the same thing:
X-Delivery-Notice: SMTP MAIL FROM does not correspond to sender.
Therefor, a concrete proposal: on encountering a formally uncorrectable
error,
1) do not notify
2) do not correct the header in place
3) do insert an X-Erroneous- before the header in question.
4) iff the header is required, insert a syntactically correct
but possibly semantically incorrect replacement.
--dave
[ps: Zmailer's author is just down the block from Cnews' author: the same
analysis may already have been done.]
--
David Collier-Brown, | davecb@Nexus.YorkU.CA | lethe!dave
72 Abitibi Ave., |
Willowdale, Ontario, | Today's featured dish:
CANADA. 416-223-8968 | Sun-dried alligator.henry@zoo.toronto.edu (Henry Spencer) (06/07/91)
In article <1991Jun7.125001.7519@newshub.ccs.yorku.ca> davecb@nexus.yorku.ca (David Collier-Brown) writes: > 4) iff the header is required, insert a syntactically correct > but possibly semantically incorrect replacement. Herein lies a serious problem, alas. Depending on the nature of the defective header, step (4) can do anything from recirculating ancient news with brand-new dates on it (so the date filters are not effective in catching it) to turning hopelessly mangled articles into superficially legal ones that duplicate existing articles but have different message IDs. The net regularly sees bursts of trash when some overambitious gateway starts sticking new message IDs on articles. Header rewriting is evil, Zmailer notwithstanding. -- "We're thinking about upgrading from | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 to SunOS 3.5." | henry@zoo.toronto.edu utzoo!henry
davecb@nexus.yorku.ca (David Collier-Brown) (06/09/91)
In article <1991Jun7.125001.7519@newshub.ccs.yorku.ca> davecb@nexus.yorku.ca (David Collier-Brown) writes: | 4) iff the header is required, insert a syntactically correct | but possibly semantically incorrect replacement. henry@zoo.toronto.edu (Henry Spencer) writes: | Herein lies a serious problem, alas. Depending on the nature of the | defective header, step (4) can do anything from recirculating ancient | news [...] Alas indeed... I knew I was stricking my neck out when I typed ``semantically incorrect''. Sure enough, head lands in basket below tumbril (:-)) --dave -- David Collier-Brown, | davecb@Nexus.YorkU.CA | lethe!dave 72 Abitibi Ave., | Willowdale, Ontario, | Today's featured dish: CANADA. 416-223-8968 | Sun-dried alligator.