Author: John W. Baxter Date: To: exim-users Subject: Re: [exim] Outlook problem
On 8/24/2004 22:45, "Mark Smith" <exim-users@???> wrote:
>
> This is rather off topic, but I can't find any information on this problem,
> so perhaps someone on this list can help:
>
> When a message being sent by Outlook is rejected at RCPT time, Outlook
> carries on sending the message regardless:
>
> Outlook log:
>
> 06:10:06 SMTP: [tx] MAIL FROM: <*****>
> 06:10:06 SMTP: <rx> 250 OK
> 06:10:06 SMTP: [tx] RCPT TO: <*****>
> 06:10:06 SMTP: <rx> 550-Verification failed for <*****>
> 06:10:06 SMTP: <rx> 550-unrouteable mail domain "example.com"
> 06:10:06 SMTP: <rx> 550 <*****> does not appear to be a valid sender
> address.
> 06:10:06 SMTP: [tx] DATA
> 06:10:07 SMTP: <rx> 503 valid RCPT command must precede DATA
> 06:10:07 SMTP: End execution
>
> Outlook then reports the 503 error instead of the 550 error, which means the
> end user never gets to see what the problem actually is.
>
> Is there any way of making Outlook give up when it sees the 550 error?
Well, you could try drop rather than deny, but that hurts if only one
recipient of several fails, and Outlook is apt to react to the drop in some
crazy way anyhow.
I'm coming to believe that when one knows one is receiving mail from one's
customers/staff/whatever-insiders that it is likely better to accept the
message and generate a bounce than to reject recipients at SMTP time.
Of course, the MUA (Outlook or otherwise) may "improve" incoming bounce
messages into incomprehensibility, just as they do things like showing only
the first or last line of multi-line [45]xx rejection messages, etc etc.
But at least the bounce leaves your server in readable form.
And the bounce may be undeliverable if the user's MUA is misconfigured.