Closed
Description
Context
A key customer complains some mails are not forwarded. That's because we do consider it as outgoing spam thus do not delevier it.
Cause
The user requested MDN
However we did not set Return-Path header causing anti-spam complains.
Not neglictible negative score due to this (1.5 magnitude)
Solution
When setting Disposition-Notification-To also set Return-Path header.
EG TB exemple:
Return-Path: <btellier@linagora.com>
Message-ID: <9719fe1a-69b8-49f3-821f-e7a5abfdcd0b@linagora.com>
Date: Wed, 4 Jun 2025 12:24:22 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Content-Language: en-US
To: btellier@linagora.com
From: Benoit TELLIER <btellier@linagora.com>
Subject: TB test
Disposition-Notification-To: Benoit TELLIER <btellier@linagora.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
TB test