Author: Pat Lashley Date: To: Exim User's Mailing List Subject: Re: [Exim] cyrus NUL failures
--On Monday, December 08, 2003 14:11:29 -0500 "Greg A. Woods" <woods@???> wrote:
> [ On Saturday, December 6, 2003 at 16:18:44 (-0800), Pat Lashley wrote: ]
>> Subject: Re: [Exim] cyrus NUL failures
>>
>> > As for trying to handle VERP-based sender addresses, well good luck.
>> > You'll fail far more often than you succeed! You can do no better than
>> > play a game of catchup.
>>
>> What is your basis for that contention? Do you know of any mailing
>> lists that use VERP but don't use the '*<localpart>=<domain>@...' form?
>
> If I'm not mistaken this "format" isn't even standardized, and certainly
> I've seen a large number of commercial mailing lists operating "in the
> wild" that don't come even close to matching this form.
I failed to note in my earlier response that I'm not attempting to
recognize -all- VERP-based sender addresses; only those which indicate
that the message was sent from a mailing list manager.
Unfortunately, you seem to be right about the lack of standards for
VERP formats. But there are only a few mailing list management packages
handlining the vast majority of all (managed) mailing lists; so it
shouldn't be too difficult to handle the majority of cases. The one
I listed above is generated by Mailman, the only VERP-using(*) list
manager for which I have examples on hand.
(*) Actually, according to the comments in the default config file, technically, Mailman's use is only VERP-like, because it is doing the
encoding itself instead of having it done in the MTA.
>> In any case, it is no more of a game of catchup than any other aspect
>> of attempting to recognize that the sender is a mailinglist address.
>
> Well, there are the de facto standards outlined and documented for
> Sendmail and all the other MTAs that work like Sendmail, then there are
> the rest. If I'm not mistaken Sendmail still, unfortunately, tops the
> list at over 70% of the working mailers on the internet, and certainly
> the vast majority of mailers on the internet work like Sendmail does in
> this respect (including Smail, and if I'm not mistaken Exim can handle
> mailing lists just like Sendmail too if one bothers to try, as could
> Postfix).
> 8BITMIME is not a standard part of SMTP, not even in RFC 2822. RFC 3030
> (defining 8BITMIME and BINARYMIME) is an optional extention only, and as
> you say it's something that must be negotiated at connection time.
> Standard SMTP messages _MUST_ be 7-bit only from beginning to end.
Standard BASIC SMTP messages MUST be 7-bit only. In fact, they MUST
be US-ASCII (defined as octets in the range 1..127). But since the
SMTP standard does allow for negotiated extensions; and RFC 1652 is
a standard specifying an SMTP Service Extension; you certainly MAY
have a standards-compliant SMTP message with (most) 8-bit characters
unencoded in the body. (I fail to see any distinction between 'standard'
and 'standards-compliant' in this context.)
[ Note: RFC 1652 defines 8BITMIME. RFC 3030 defines CHUNKING (the
BDAT verb) and BINARYMIME. BINARYMIME may only be used with CHUNKING.
8BITMIME may be used with CHUNKING, but does not require it.]