Re: [Exim] Two local_scan functions - request for comments.

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Συντάκτης: Matthew Byng-Maddick
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Προς: exim-users
Αντικείμενο: Re: [Exim] Two local_scan functions - request for comments.
On Tue, Mar 26, 2002 at 11:05:04AM +0100, Patrick von der Hagen wrote:
> But second, I'd expect exim to detect a timeout and react accordingly.
> Since TCP is no stateless connection, the sending of a 250-message to
> accept a mail should return an error-code. I'd be very surprised if
> Phil did not check this error code.


This would potentially break reliable mail delivery. Think about the
situation where it's actually the link that's gone down in between the
two machines, and you don't know at what time the other end has stopped
being able to see your machines. By the time you send 250, the message
should be queued for delivery.

RFC2821 S6.1 "Reliable Delivery and Replies by Email"

| When the receiver-SMTP accepts a piece of mail (by sending a "250 OK"
| message in response to DATA), it is accepting responsibility for
| delivering or relaying the message. It must take this responsibility
| seriously. It MUST NOT lose the message for frivolous reasons, such
| as because the host later crashes or because of a predictable
| resource shortage.


Note the last sentence in particular.

MBM

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Matthew Byng-Maddick         <mbm@???>           http://colondot.net/