Re: [ietf-smtp] DSNs

John Levine <johnl@taugh.com> Sun, 26 April 2020 22:22 UTC

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From: "John Levine" <johnl@taugh.com>
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Subject: Re: [ietf-smtp] DSNs
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In article <cone.1587934924.981704.31890.1004@monster.email-scan.com> you write:
>Incoming mail is addressed to a valid mailbox. Your MTA accepts it. As such,  
>the sender already knows it is a valid recipient.
>
>I don't follow what information is getting leaked, if a second later a  
>success DSN gets sent to the sender. The sender already knows it's a valid  
>mailbox, by the virtue of the fact that the mail was accepted.

Not necessarily.  It might be forwarded, it might bounce later.

We can bikeshed forever about whether you send a success DSN if it's
delivered to a spam folder.

R's,
John