Re: [ietf-smtp] DSNs

Sam Varshavchik <mrsam@courier-mta.com> Tue, 28 April 2020 12:19 UTC

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From: Sam Varshavchik <mrsam@courier-mta.com>
To: ietf-smtp@ietf.org
Date: Tue, 28 Apr 2020 08:19:09 -0400
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Subject: Re: [ietf-smtp] DSNs
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John Levine writes:

> In article <cone.1588025328.577835.59133.1004@monster.email-scan.com>om>,
> Sam Varshavchik  <mrsam@courier-mta.com> wrote:
> >I do agree that I don't /quite/ see the value-added to the recipient of
> >implementing success DSNs. Or any DSNs, for that matter. If the receiving
> >mail server does not want the email it should reject it instead of accepting
> >it and generate a failure DSN.
>
> In general I agree but there are still situations where an MTA (mine
> for example) accepts a message intending to forward it somewhere else
> and then the forward fails.  Either send a DSN or drop it on the floor
> at that point.

Well, yes. You take ownership of that message by the act of forwarding, you  
now own it, from the point of forwarding. If you don't want to disclose the  
forwarded-to address, that's your responsibility, so either set the sender's  
address to <>, or to some other address where you want the bounces to go.

Presuming that you decide to keep the original MAIL FROM, you obviously made  
the decision to forward your mail knowing, fully well, that in the event of  
a problem your forwarded-to address is going to be visible. This is not an  
inherit problem with DSNs. That's how they work.