Re: [exim] Multi-line 5xx response (at DATA time)

On Sat, 9 Apr 2005, Edgar Lovecraft wrote:

> Over a year ago I moved everything to a single line http link.

Do you mean that you link to static pages with a generic explanation
for each of your various causes of rejection; or do you mean that a
custom page is composed with details for each rejection (and if so,
how long does that page persist before you garbage-collect?).

The problem I was stuck with, was that senders are producing "To:"
headers with dozens of addresses in them, and there's a syntax error
somewhere in there. Mostly (though not exclusively) these syntax
errors are produced by remote senders who are users of MS Exchange.
Somewhere hidden deep in the general mess of quotes and apostrophes
that Exchange has donated to their addressee list, there's a syntax
error. exim has reported exactly what the error is, which would make
it trivial for the sender to locate the error, if only Exchange would
deliver exim's response verbatim back to the sender (and/or to their
mail support). But it insists on telling them something different
(and untrue, as I remarked before) along with only the first line of
our multiline response.

I posted an example earlier on the thread:

550-Rejected after DATA: malformed address:
550-'>\n may not follow <'flavell@???:
550-failing address in "to" header is: <'flavell@???'>
[...and so on...]

It needs for them to get at least this amount of information, if
they're to stand any chance of locating the syntax error amongst the
dozens of addresses in their addressee list. This is the dilemma.

Just pointing them to a generic web page which explains that we reject
header syntax errors as determined by the applicable RFCs, wouldn't
really be of much help to them, in this kind of situation. Which is
why I'm interested to know if anyone has successfully implemented
web-based custom rejection notices.

thanks