Re: bounce, mta, & mua (was Re: sieve draft)

Tim Showalter wrote:

> Nailing it down limits the applicability of the draft. What does it change?
Hmm, would rather say that it makes the applicability clearer for
the implementors. But it depends on how specialized or generic you
want Sieve to be. I think Sieve is enough special to deserve an
explaination in what circumstances it is intended to be used.

> Rationale: I don't understand the difference between MTA and MUA filtering.
I admit, it _is_ confusing.
I have been asserting that there are a difference, of which I have
tried to explain my view on what the differences are. But that does
not mean that I am the one to be right. Therefore, this discussion
helps a lot to put things in perspective.

When you bring up Cyrus as an example of MTA filtering you should
note that although the filtering is typically done by using the
.forward mechanism calling something like procmail, it could just
as well have been done by the deliver(8) program, which is
distributed as part of the cyrus package, which I essentially
regard as a system for message storage.

Personally I regard the POP3 protocol as a a maildrop forwarding
protocol. The end user are therefore restricted to perform post-
delivery filtering only when the maildrop have been forwarded to
where the message store is situated and where access to personal
folders is possible. In the case of a POP client, this is the
same as the local PC (or equivalent).

An interesting question: are POP clients supposed to be able to
generate DSN's? That might put some arguments on it's head. :-)

-- 
Hälsningar/Regards

Tomas Fasth <tomas(_dot_)fasth(_at_)twinspot(_dot_)net>
tel: +46-13-218-181 cel: +46-708-870-957 fax: +46-708-870-258
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