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When I send an email from noreply@mysite.com to user@yahoo.com and I use that VERP bounce format like bounce+user=yahoo.com@mysite.com

Is this bounce back sent to the mail server in DNS records of the sending domain or is it sent back to the IP address of the mail server that sent the message ?

adrianTNT
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1 Answers1

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The return path for bounces is determined by the envelope sender (the MAIL FROM line in the smtp protocol). In the mail headers this is generally copied to the Return-Path header. Here's an example of a mailing list mail that specifies bounces should go to the mailing list server instead of the sender of the mail:

Return-Path: <git-owner@vger.kernel.org>
From:   Sun He <sunheehnus@gmail.com>
To:     git@vger.kernel.org
Subject: [PATCH v2] Replace memcpy with hashcpy when dealing hash copy
 globally
Dennis Kaarsemaker
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  • So it is OK and reliable to use a return path like `bounce+user=yahoo.com@mymailserver.com` instead of `bounce+user=yahoo.com@mysite.com` ? For some reason I thought it should return to @ same domain. – adrianTNT Mar 02 '14 at 12:06
  • the return path of a mail should be an address that can deal with bounces. For personal mail it should be the sender, for list mail the bounche handler of the list and for commercial mail the thing that unsubscribes people for instance. – Dennis Kaarsemaker Mar 02 '14 at 12:10
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    Return path for bounces is determined by envelope sender - email used in "MAIL FROM:" command in SMTP session. Many mail servers copy envelope sender into "Return-Path:" header. – AnFi Mar 02 '14 at 16:09
  • @AndrzejA.Filip you're right. I amended my answer to be more correct. – Dennis Kaarsemaker Mar 02 '14 at 17:17