I have a Docker-based mail server (Mailu) setup. It's working great except for delivery reports which are sent automatically (one of the user mailboxes is full and a "Quota exceeded" notification is sent to the sender).
The reports are rejected by the recipient due to DMARC failure:
This is an email abuse report for an email message received from IP xxx.xxx.xxx.xxx on Tue, 28 Sep 2021 05:16:31 +0000.
The message below did not meet the sending domain's dmarc policy.
The header of the rejected message:
Feedback-Type: auth-failure
User-Agent: Lua/1.0
Version: 1.0
Original-Mail-From:
Original-Rcpt-To: [email protected]
Arrival-Date: Tue, 28 Sep 2021 05:16:31 +0000
Message-ID: <[email protected]>
Authentication-Results: dmarc=fail (p=reject; dis=reject) header.from=domainB.com
Source-IP: xxx.xxx.xxx.xxx
Delivery-Result: reject
Auth-Failure: dmarc
Reported-Domain: domainB.com
The mailserver runs on mail.domainB.com, has domainA.com configured, and the email is sent to [email protected].
SPF is configured for both domains:
- Domain A:
v=spf1 a mx include:domainB.com -all
- Domain B:
v=spf1 a mx include:_spf.google.com include:servers.mcsv.net include:relay.mailchannels.net -all
DMARC for both: v=DMARC1;p=reject;rua=mailto:[email protected];ruf=mailto:[email protected];adkim=s;aspf=s;fo=1;
MX for both domains is mail.domainB.com and the PTR record for the IP "xxx.xxx.xxx.xxx" points to srv.domainB.com. All domains run on and point to the same server.
I suspect a DNS/DMARC configuration error but I can't point it out. Do I need to include the domain domainB.com in the SPF as well (see header.form).
Edit: Some messages contain a message body (in addition to the header above):
Received-SPF: None (no SPF record) identity=no SPF record; client-ip=xxx.xxx.xxx.xxx; helo=mail.domainB.com; envelope-from=<>; receiver=<UNKNOWN>
DKIM-Filter: OpenDKIM Filter v2.10.3 mx.hostpark.net F224D16527
Received: by mail.domainB.com (Postfix)
id 61B3BDFF1; Wed, 29 Sep 2021 06:16:50 +0000 (UTC)
Date: Wed, 29 Sep 2021 06:16:50 +0000 (UTC)
From: [email protected] (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: [email protected]
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
boundary="25F89DFEB.1632896210/mail.domainB.com"
Message-Id: <[email protected]>
Could anyone point me in the right direction? Much appreciated, thanks!
