Autor: John W. Baxter Fecha: A: Exim users list Asunto: Re: [exim] exim 4.4 authentication
On 3/14/2005 2:43, "Alan J. Flavell" <a.flavell@???> wrote:
> There is still one problematic area with that, however. When users
> contrive to produce a mail which the server rejects (e.g they try to
> send a mail with its envelope-sender set to a defective address, or
> with broken header syntax etc.) then it seems some clients get very
> confused by the 5xx response from the server.
When we're talking to "ordinary" user machines, we don't reject at SMTP
time...we accept and produce bounces. When we talk to the world, we reject
at SMTP time.
Having split the MX IPs from the submission IPs has made this pretty easy.
Even the MUAs that do things right (rather than showing only the first line
or only the last line of multi-line responses), the user of the MUA becomes
confused. Especially if the MUA sends pending mail before receiving...then
we used to get calls about "I can't get my mail" which turned out to be "I
mistyped someone's address" or "I foolishly replied, and the sender messed
up her From: or Reply-To: header."