named-data.net

Gmail is classifying emails from Redmine as spam, because they are in violation of Google's recommended email sender guidelines.

Gmail requires:

1. Use a consistent IP address to send bulk mail.
2. Keep valid reverse DNS records for the IP address(es) from which you send mail, pointing to your domain.
3. Use the same address in the 'From:' header on every bulk mail you send.
4. (IPv6) The sending IP must have a PTR record (i.e., a reverse DNS of the sending IP) and it should match the IP obtained via the forward DNS resolution of the hostname specified in the PTR record. Otherwise, mail will be marked as spam or possibly rejected.
5. (IPv6) The sending domain should pass either SPF check or DKIM check. Otherwise, mail might be marked as spam.

Headers from one of such emails include:

Return-Path: <[email protected]>
Received: from named-data.net ([2607:f010:2e8:77:edde:8fc8:84e2:a325])
        by mx.google.com with ESMTP id jv8si42345525pbc.136.2015.09.16.10.57.56;
        Wed, 16 Sep 2015 10:57:57 -0700 (PDT)
Received-SPF: neutral (google.com: 2607:f010:2e8:77:edde:8fc8:84e2:a325 is neither permitted nor denied by best guess record for domain of [email protected]) client-ip=2607:f010:2e8:77:edde:8fc8:84e2:a325;
Authentication-Results: mx.google.com;
       spf=neutral (google.com: 2607:f010:2e8:77:edde:8fc8:84e2:a325 is neither permitted nor denied by best guess record for domain of [email protected]) [email protected]
Received: from named-data.net (localhost [127.0.0.1])
    by named-data.net (8.14.4/8.14.4/Debian-2ubuntu2.1) with ESMTP id t8GHw9ME012776;
    Wed, 16 Sep 2015 10:58:09 -0700
Date: Wed, 16 Sep 2015 10:58:09 -0700
From: [email protected]
Message-ID: <redmine.journal-12804.20150916175809.204aa43293acfe1d@named-data.net>

This email violates Google guideline item 2,4,5. A violation of item 4 will definitely cause the email to be classified as spam.

Corrective actions required:

• add a PTR record for the Gerrit email server 2607:f010:2e8:77:edde:8fc8:84e2:a325
• add an AAAA record to point to this IP
• add an SPF record to permit this IP to send emails on behalf of named-data.net domain